NEWS

PROCEEDINGS OF SOCIETIES.

ROYAL SOCIETY. Thursday, April 7, 1864.

Major-General SABINE, President, in the Chair. THE first paper was by Dr. DICKINSON, "On the Functions of the Cerebellum," communicated by Dr. BENCE JONES. The writer glanced over the suppositions that have been made at various times as to the functions of this important division of the brain. It has been imagined to be the seat of memory because of its hardness, and from the fact that one is apt to scratch the back of the head when thinking. Some have supposed it to be a second brain, to be the source of involuntary motions, to regulate the motions of the heart and of respiration, a seat of sensation (from the situation of the origin of the fifth cranial nerve), the centre for movements in general, for the functions of reproduction, for co-ordinating bodily movements, for harmonising movements, &c. The author considered none of these functions strictly appropriate to the cerebellum, and has performed a series of experiments with a view to decide this question. The same great divisions of the nervous system can be traced in all the vertebrate animals in which it attains any development, namely, the cerebrum, the cerebellum, and the medulla oblongata and spinal cord. It may be concluded that the functions of each part are to some extent the same in all animals, and in this case a series of experiments on the effects produced by the removal of the different parts would afford data, even if the lower animals were the patients, from which the functions of the same organs in animals higher in the series might be inferred; these latter not admitting of experiments being performed on them, the results being mixed up with the effects of the injury. The course he followed was to remove both cerebrum and cerebellum, leaving only the medulla oblongata, and to compare the effects with those produced by the removal of the cerebellum alone, and of the cerebrum alone. It would take too much space to give a detailed account of all the experiments performed, but it may be stated that with the lower animals, such as reptiles, the effect of a removal of both cerebrum and cerebellum was to take away all voluntary power in the field snake, which remained motionless; the frog performed regular but tardy movements; the salamander was motionless except when irritated; the toad, although it could not walk or swim, tried to turn when laid on its back; the tortoise performed some apparently voluntary motions when irritated, but all movements ceased in twenty-four hours; the eel wriggled, but there were no voluntary movements. When fishes were the objects of the experiments the removal of both cerebrum and cerebellum took away almost all evidence of life, although in some cases respiration and slight convulsions were observed. On submitting the higher animals to a similar mutilation speedy death interfered with observation of the results. The general effects of removal of the cerebellum alone were to produce a loss of activity and of the power of co-ordinating movements, so as to retain the balance, &c., a greater effect being produced on the hind than the fore quarters. A curious stilted motion was observed when the animals walked. The effects of loss of the cerebrum were a loss of vigour, but the animal appeared capable of performing all motions. There were, however, differences according to the place of the animal in the scale of beings. An experiment on the contractile power of the muscles after injury of the cerebellum was tried on the water tortoise. The effect of an injury on one side only was to cause only a slight loss of contractile power, but the opposite limb was always extended. The general result arrived at was that the cerebellum was not concerned in the production of heat, of the secretions, of the motions of

copulation, of general motion, or of general sensation. In snakes it appeared that each of the three divisions of the great nervous centre were concerned in the production of motion; in fishes the medulla alone was not sufficient to produce voluntary movements, and in the absence of the cerebellum there was not a proper adjustment of motion; in fishes and reptiles the cerebrum and cerebellum both shared in producing voluntary motions. The fore parts of animals seemed to be dependent more immediately on the cerebrum, the hinder parts on the cerebellum; the cerebellum seemed to regulate habitual movements, and the cerebrum, impulsive movements proceeding more directly from the will. In cases of human beings with congenital absence of cerebellum, there was a want of power of voluntary movement in the muscles of the lower extremity. It would appear that each lobe is in connexion with all four limbs. The author considered that the cerebellum had nothing to do with general sensation, or with any particular sensation. He advanced an hypothesis that, as the cerebellum consisted of two parts, it had two duties, the outer layer being the seat of voluntary motor power, while the inner was concerned in co-ordinating movements. Professor SYLVESTER then read a paper entitled, “An Inquiry into Newton's Rule for the Discovery of Imaginary Roots, together with an Introduction to the Theory of Algebraical Equations with Conjugata Co-efficients." He stated that Newton himself had not furnished us with a demonstration of the rule, nor had he left behind him a record that he had succeeded in accomplishing a demonstration, so that its discovery was still desirable. The author did not profess to have furnished a perfectly general demonstration, but only to have made some steps towards it; equations of the fifth degree, however, presented some difficulty. The Professor entered into various questions connected with these equations, such as the curves that they might represent, &c.; but the subject being of such an abstruse nature, he only glanced cursorily over these points.

A communication from Mr. GASSIOT, being a description of a train of eleven bisulphide of carbon prisms arranged for spectrum analysis, was then read. The description of the apparatus was one of the points of interest. In its construction many difficulties had to be overcome, one of which arose from the circumstance that the cement employed to fasten the sides of the prisms to the ground-glass bottles forming their body was apt to cause the glass plates forming the sides to warp. To obviate this, a second piece of crown glass was pressed on the surface of each side, a thin layer of castor oil being interposed to prevent reflection from so many surfaces. A great advantage was gained by having these exterior pieces of glass wedge shaped, the wedges being so placed that they acted antagonistically to the bisulphide prisms, thereby diminishing the refraction without materially altering the dispersion. In this manner eleven prisms could be employed without blending the ray to an inconvenient extent, whereas otherwise only seven could have been used. On examining the double line D after passing through this train, it was found that its two components are separated three minutes and six seconds, and that there was a third line exactly equidistant between them, together with other lines filling up the intermediate space as had been before observed, as shown in the accompanying diagram; but the most re

Violet en d.

Red

THE Secretary read the minutes of the two preceding meetings (the second being the anniversary on March 3c), both of which were confirmed by the Chairman. It was then stated that a resolution of the Council would be proposed at a future meeting, the requisite formal notice of which was now given, to the effect that the following gentlemen be elected Foreign Members of the Society, viz., MM. Dessaignes, Erdmann, and Von Fehling.

The formal admission of Mr. Henry Bassett, Mr. Coleridge Pole, and Mr. C. Greville Williams was declared by the President, after which the members proceeded to ballot for the election of Mr. Wentworth Lascelles Scott, who was unanimously elected a Fellow of the Society.

The SECRETARY then read a paper "On Oxyaniline," by Dr. Schmidt, student in Professor Kolbe's laboratory. The author commenced his researches with nitro-salicylic

acid, which was known to form an amido-acid having the

formula

HO(C12 {N} 02(C20,0

By submitting this amido-salicylic acid to destructive distillation, it was found to split up into carbonic acid and a white crystalline substance for which the name of oxyaniline was proposed. The acid should be mixed with twice its weight of powdered pumice stone before being heated, and however carefully the process was conducted, a small quantity of a fusible brown product was volatilised along with the oxyaniline. This impurity could be removed by digesting with alcohol mixed with a small proportion of acetic acid, wherein it was freely soluble. The equation explanatory of the formation of oxyaniline was thus represented :HA

HO(C12

Oxyaniline.

Amido-salicylic acid. The properties of oxyaniline were thus described:-The pure sublimed product took the form of definite white needles, which were soluble in water, forming a solution which soon acquired a brown tinge by spontaneous decomposition. This liquid became coloured of a deep indigo on the addition of alkalies, and was again bleached by the action of acids. The aqueous solution had the power of reducing the compounds of the noble metals, becoming, at the same time, changed to a violet liquid. Oxyaniline unites with hydrochloric, hydrobromic, hydriodic, and other acids, forming salts, which, when perfectly neutral, were liable to spontaneous change, but when containing excess of acid were quite

permanent.

The PRESIDENT considered these results especially interesting at a time like the present when aniline and aniline compounds were engaging a large share of scientific attention. With reference to the relation subsisting between salicylic acid and the members of the phenyl group, it was remarkably how widely different were the physical properties of the ordinary hydrated oxide of phenyl from coal tar, and that obtained by the action of heat upon salicylic acid. The two bodies were perfectly isomeric, although they exhibited certain differences in their deportment with pentachloride of phosphorus.

Dr. FRANKLAND believed that the new process of Dr. Schmidt would offer an insight into the molecular constitution of this class of bodies. The author had written the

The equivalentic value of carbon used by Professor Kolbe and Dr. Schmidt remaining the old number 6. The speaker also suggested that the determination of the monobasic or bibasic character of the body would afford a further clue of great value.

Mr. HENRY BASSETT was then invited to read a paper "On the Sub-formiate of Ethyl, and on the Basic Salts of some Organic Acids." The author commenced by referring to a preliminary account of the preparation of the subformiate, which had already appeared in the seventh volume of the CHEMICAL NEWS (page 158), and pointed out the advantage of proceeding in the manner then indicated; for by reversing the steps in that process, viz, by adding ethylate of sodium to the chloroform, a considerable loss of product was occasioned by a secondary reaction, in which a copious evolution of carbonic oxide gas occurred. The partial destruction of the compound under these circumstances was thus represented :— C2H2O= 2 (CH)} 03 + Na

O=CO+CHNaO, + C}o

C2H2O. +3 CH

It would be observed that this equation accounted for the production of ether and alcohol which had been noticed by Messrs. Williamson and Kay when using dry ethylate of sodium in their experiments of 1854. The mode of preparation recommended by the author was very simple, and usually gave a product nearly equal in bulk to the chloroform used. 18 ounces of absolute alcohol were mixed with 3 ounces of chloroform in a flask provided with a long glass tube to serve as a condenser, 1 ounce of sodium, cut into small pieces, were then gradually added, its action being assisted by a gentle heat in the water bath. The alcohol was then distilled off and the residue dissolved in water, when the supernatant oil, dried over chloride of calcium and rectified, answered perfectly to the pure tribasic formiate of ethyl- CH"

(CH)03.

The author then proceeded to describe the preparation of the tetrabasic carbonate of ethyl, viz., by gradually adding the proper quantity of sodium to a mixture of chloropicrin and absolute alcohol, the mixture being heated in a water bath, then distilling off the alcohol, and dissolving the residue in water, when the substance in question floated upon the surface of the aqueous solution. The reaction was as follows:

C

CNO2Cl3+40=3NaCl + NaNO2+ (C,H2),} ° The pure substance boils at 158°-159° C., and has a specific gravity 925. Two analyses gave results closely agreeing with the theoretical composition, as also did a determination of the vapour density. When boiled with alcoholic potash, the substance deposited a considerable quantity of the alkaline carbonate.

Some of the substance was digested for six hours in the water bath with boric anhydride, and the result distilled; the distillate after purification consisted entirely of ordinary carbonic ether, as was shown by an analysis. The boiling point also was 125°C. This decomposition was thus explained :

Thus indicating the probable existence of two distinct | series of isomeric bodies-one derived from the fatty acids and the other from the triatomic alcohols. The author suggested the possibility of producing the glycidic ethers directly from the glycerides by the action of boric anhydride, and concluded with some general remarks upon the basic salts of certain organic acids.

The PRESIDENT believed he was correct in affirming that there was a discrepancy between the experiences of Mr. Bassett and of Mr. Lockwood, who formerly worked in his own laboratory at University College. Some time had elapsed since the last-named gentleman made the observation that tetrachloride of carbon, as prepared by passing a mixture of chlorine and chloroform vapour through a heated tube, acted very powerfully upon the ethylates of potassium and sodium, and gave rise to a violent evolution of mixed gases, particularly carbonic anhydride and olefiant gas, with a large quantity of ether vapour, were given off, whilst an alkaline chloride was formed. If his memory had not deceived him, the statement of these independent results showed a divergence which was worthy of further investigation. If these observations could be repeated under circumstances so modified that the action should not, on the one hand, be so violent as Mr. Lockwood had represented, nor so feeble or indifferent as Mr. Bassett had just now described, there was a probability of some useful results being obtained.

Mr. BASSETT explained that the method which he had followed in the preparation of tetrachloride of carbon was that of exposing chloroform to sunlight for several days in an atmosphere of chlorine gas. The product so obtained had certainly no energetic action upon the alcoholic solution of ethylate of sodium; there was no gas given off, and the only product yielded, whether in sealed tubes or at the boiling point of alcohol, was a brown substance, which resisted the solvent action of all the liquids he had tried, and appeared altogether unpromising in character.

At the conclusion of the ordinary business of the meeting, Mr. SEPTIMUS PIESSE rose to call the attention of the Society to an announcement which appeared in the Times and other newspapers of that day to the effect that a sum of money, amounting to upwards of 100cl., had already been subscribed for the purpose of erecting and endowing almshouses in Penzance as a lasting memorial to the great English chemist Sir Humphry Davy. Whether this or other form of recognition, a statue, for instance,-be ultimately determined upon, the speaker considered it desirable that the Society should take united action in giving support to the movement, and in endeavouring to secure the erection of a worthy monument to so eminent

a man.

The PRESIDENT thanked Mr. Piesse for calling the attention of the Society to the subject, and requested him to

prepare a formal resolution upon which the Council might take action.

The meeting was then adjourned until the 21st inst., when Mr. J. T. Way will deliver a discourse "On the Philosophy of British Agriculture.”

CHEMICAL GEOLOGY,

A Course of Twelve Lectures, by Dr. PERCY, F.R.S. Delivered at the Royal School of Mines, Museum of Practical Geology, Jermyn Street.

LECTURE IX.-Thursday, January 21, 1864. LADIES AND GENTLEMEN,-We now proceed to the consideration of sea water.

The subject of sea water is, indeed, a grand one. We are indebted to Forchammer for some of the best researches -about the most recent as well as the most elaborate. I propose, in the first place, to examine carefully all the elements which have been clearly detected in sea water. No doubt there are many which have eluded our means of analysis. We cannot go beyond a certain point. We have received great aid of late from spectrum analysis, by means of which we are enabled to determine the presence of certain elements by the agency of light. Our senses may afford us evidence of the existence of certain substances, although we may be unable to find them out by our ordinary processes of analysis. Let us take the familiar examples of odours. A small grain of musk may scent a large room, and we know perfectly well that the musk must be there; but although we are sure of its presence, we should be unable to detect the musk by chemical analysis, and thus the power of scent may go far beyond the powers of the greatest chemist in the world.

Twenty-seven distinct elements have been found in sea

water.

First of all, there is the water itself. That is composed of oxygen and hydrogen in the proportion of eight parts, by weight, of oxygen to one of hydrogen. Then there is the oxygen dissolved in the water. All water contains oxygen or air dissolved, and the oxygen is dissolved in a greater proportion than the nitrogen of the air. It is this oxygen which is essential to the existence of animal life in the ocean, or in waters generally. Ocean water contains a little organic matter, and of that oxygen is a constituent. We have, then, oxygen as an essential constituent of the water, oxygen dissolved in the water, oxygen as a constituent of the organic matter in the water, and, again, as a constituent of the bases, and of certain acids existing in sea water.

Hydrogen forms one-ninth of the water. It also is a constituent of the organic matter found in the water.

Chlorine forms the largest proportion of the solid ingredients of sea water, existing in combination with various metallic bases, such as calcium, magnesium, and sodium. Next in order comes bromine, which is also present in sea water, and is, in fact, extracted from sea water. It is obtained from the mother liquor, resulting from the evaporation of sea water and the crystallisation of its salts.

Some

Then comes iodine, which is extracted from sea water, and which can only be derived from sea water. years ago elaborate researches were made with regard to the association of the three elements-chlorine, bromine, and iodine-with each other, especially by a chemist of Turin. It was found that they were always in association. Wherever chlorine was, there were traces of bromine and of iodine.

There are two ways in which we can prove the existence of elements in sea water,-first, directly in the water itself by the aid of chemical analysis; and secondly in the plant and animal structures existing in the water, and which can certainly derive their materials only from the water. The one kind of evidence is, I think you will admit, as conclusive as the other, Fluorine is found in

the roots of corals. When these are dissolved by hydrochloric acid and precipitated by ammonia, the deposit contains fluoride of calcium-fluor spar, in fact. Forchammer obtained fluorine by the direct evaporation of 100 lbs. of sea water from the Sound of Copenhagen until the common salt obtained began to crystallise. He then added ammonia, digested the precipitate with sal ammoniac, collected the residue, and ignited it. It consisted of phosphate of lime-that is, apatite and fluoride of calcium. You will see one or two curious points in connexion with this presently. It weighed from the 100 lbs. of water as much as 31 grains, which is a large amount for the chemist. He easily found fluor spar in the deposit of the boilers of Atlantic steam ships. There is, then, no doubt whatever of the presence of fluorine in sea water.

Sulphur exists in combination with oxygen, forming sulphuric acid. This sulphuric acid is combined with the bases in the water. Sea water, when free from organic matter, may be kept undecomposed in bottles for many years, but when it contains the remains of microscopic animals it undergoes decomposition, and sulphuretted hydrogen is evolved. The sulphuric acid of the salts gets reduced by the presence of organic matter. The largest quantity of sulphuretted hydrogen was found in the water, near the mouth of the river La Plata. The average relation between the chlorine of sea water and the sulphuric acid is as 100 to 11.89. It is very interesting to study the constitution of sea water in this way. I have taken chlorine, the most abundant constituent, as the standard of comparison, and represent it by 100.

Phosphorus is always present, and exists in the state of phosphoric acid. In the evaporated residue washed with water, phosphate of lime is found along with carbonate of lime, fluoride of calcium, sulphate of baryta, sulphate of strontia that is an interesting point- and silica. There is good reason to believe that there are also borates of lime and magnesia. We shall see the evidence of this directly. Carbon exists in sea water as free carbonic acid, and as a constituent of the organic matter which may be present, and in very small quantity as combined with lime. Forchammer tells us that all sea water reduces hypermanganate of potash, and therefore contains organic matter, the reduction being effected by means of such matter.

of more novelty, if not of greater interest. It was, however, again introduced by Professor Redwood, who, in a paper "On Percolation," once more went over the history and rationale of the process, the arguments for and against its application to the making of tinctures, and the advantages and disadvantages of certain forms of percolators. With all this we may assume that our pharmaceutical readers are well acquainted, but we may give a brief summary of the paper. Introduced into pharmacy between thirty and sixty years ago, the use of percolation has gradually extended, but in no country and at no time has it completely superseded the older and simpler plan of making tinctures by maceration. There is no difference of opinion about the use of it as a means of effecting the complete exhaustion of a material, and it is specially applicable for making concentrated tinctures, like essence of ginger. But no fixed rules can be laid down so as to enable an inexperienced operator to conduct the process successfully, and it becomes dangerous in the hands of a careless or unskilled person. In general, materials to be operated upon require to be in as fine a state of divisior as is compatible with uninterrupted percolation. It must be remembered that it is not sufficient for the liquid to pass over the surface of the particles of the material. It must permeate their substance by capillary attraction and circulate through the mass, so that the successive particles of liquid may come in contact with the molecules of solid matter, until all the soluble portion has been imparted. In this it differs from maceration, in which process the material may be said to act like a sponge in absorbing the menstruum where it remains quiescent, while in percolation there is a constant change of particles caused by the hydrostatic pressure of the column of liquid. The advantage of the process of percolation is, that by its means the whole of the dissolved portion is recovered, while after maceration a considerable quantity will remain in the mass, even after it has been submitted to great pressure. There are differences of opinion about the best form for a percolator. A few persons prefer a cylindrical, but the general opinion is in favour of the conical form. The objections to a cylindrical percolator are, first, that when the material becomes saturated with the menstruum it is apt to swell and impede percolation; second, that a substance, like opium, containing much soluble matter, becomes reduced in bulk, and, shrinking away from the sides, leaves a channel for the menstruum to pass without permeating the material; and third, that from the disposition of a liquid passing down a cylinder to aggregate towards the centre, there is always left near the bottom a portion of material through which the percolation has been imperfect. All these objections are obviated by the use of a conical percolator. In the first case, when the mass swells it only rises and accommodates itself to the shape of the vessel; in the second, when it contracts it only settles down, and still remains adherent to the sides; and the third objection is of necessity obviated by the shape of the vessel. In the course of his remarks, Dr. Redwood strongly condemned the practice of displacing, or endeavour

(To be continued.)

PHARMACEUTICAL SOCIETY.
Wednesday, April 6.

Mr. SANDFORD, President, in the Chair. THE subject of percolation may be said to be as completely exhausted as any substance that was ever submitted to the process, and might now be displaced by another topic

and showed that, while it was possible to displace water by means of spirit, water added to a spirituous mixture immediately mixed with it. The practice, he said, only resulted in the deterioration of the tincture. Dr. Redwood came lastly to a form of apparatus he has devised for making tinctures by a process which he believes to be an improvement of that of the British Pharmacopoeia. This apparatus consists of a cylindrical vessel with a rounded bottom, and furnished with a tap. It holds threefourths of the menstruum, as directed in the Pharmacopoeia, in which the materials to be macerated can be suspended in a flannel bag. This is so far a modification of Dr. Burton's displacement apparatus, and our readers will see that no necessity for agitating the materials exists. When the period for macerating has expired, the fluid may

be drawn off, and then a metal cylinder passed down within the flannel bag, so as to enclose the materials, forms a percolator with a flannel bottom through which the remaining fourth of the spirit may be passed. To carry out the last part of the process, it is only necessary to withdraw the metal cylinder from the bag, which can then be placed under the press, and so the whole of the process carried out with the utmost ease.

Mr. DEANE, who has given great attention to the process of percolation, then made some remarks, in which he stated that, from his experience, the process was not one which could be safely left to any one to carry out. It required special skill and attention to many particulars. He then alluded to his first experiments with a cylindrical percolator, and the discovery which led him to adopt the conical form, namely, the fact that at the bottom of the cylinder there was always left an angular space through which the menstruum did not pass. Mr. Deane then dwelt on the necessity of a tap or some other contrivance for regulating the flow of the liquid-a point which requires special attention. He recommended that, before packing the materials, they should be wetted with half their weight of the menstruum, so as to drive out the air from the intercellular spaces, and so avoid the formation of channels through the mass in the percolator. In general, he said, it would be that a quantity of menstruum four times the weight of the materials would be sufficient to exhaust them. In some cases five or six times the weight might be required, but in no case less than three times, and therefore the quantity of spirit ordered in the Linamentum Belladonæ, P.B., was not sufficient.

Mr. HILLS, in a few words, expressed a strong opinion in favour of maceration as a method of making tinctures. The meeting then adjourned.

We may here supply an omission from the report of the previous Pharmaceutical meeting, at which Mr. Haselden read a paper on "Percolation," and exhibited a new form of percolator intended to carry out the instructions of the British Pharmacopoeia. The percolator is made of blocktin, and is furnished with a tap at the bottom, by which the operator is able to macerate as long as required before the fluid is allowed to pass through; it is cylindrical, and furnished with a moveable perforated diaphragm, about two inches from the bottom, resting upon four supports; the ingredients are placed upon this diaphragm, and threefourths of the spirit poured on as directed; a portion passes through and fills up the space between the bottom of the percolator and the diaphragm, so that the material while macerating is surrounded by the liquid; it can be well stirred during this primary part of the process. At the expiration of forty-eight hours the tap is turned, and the tincture or liquor allowed to pass through into a glass receiver, of almost any size, fitting the tap by means of a shive; that completed, the second perforated diaphragm is placed upon the top of the material, and the remainder of the liquid added. This having ceased to percolate through, the marc, as directed, is taken out, pressed, and the liquor mixed with the other portion, and the quantity of spirit added to make up the full measure of one or two gallons, as the case may be. The quantity of proof spirit lost in making two gallons of compound tincture of cardamoms was only eight ounces, and the colour and taste of the product were excellent.

Two supplementary meetings are announced for the discussion of the Pharmacopoeia.

ACADEMY OF SCIENCES.
April 4.

A MEMOIR "On the Alcoholic Fermentation," by M. Béchamp, was read. The author remarks that two orders of ferments exist-one soluble, and therefore not organised, of which diastase may be taken as the type, the other organised, and therefore insoluble. The action of the

former is invariable and specific; that of the latter, in a chemical point of view, is essentially variable, like that of all organised beings. The so-called fermentation of cane sugar set up by beer yeast is thus explained :-The yeast plant first of all transforms cane sugar into glucose outside itself by means of a product which it contains ready formed in its organism, and which the author calls zymase; the plant then absorbs the glucose, digests and assimilates it, grows and multiplies, and finally throws off the used parts of its tissues in the form of the numerous compounds known as the products of fermentation, just as human beings throw out their waste in the form of urea, &c. According to this theory the alcohol, &c., must come from the yeast, and should be obtained from yeast perfectly free from glucose, which the author's experiments prove does in fact furnish alcohol. M. Béchamp found also that the Mycoderma Aceti in contact with canesugar yielded alcohol, which it is thus seen may be formed without sugar by yeast, and with sugar by another organism similar to yeast. Hence it is clearly impossible at present to express the so-called fermentation changes by an equation. The author considers them as a series of transformations which take place simultaneously or consecutively, and which may some day be individually explained by an equation comparable to that which expresses the change in starch under the influence of diastase.

In a paper "On the Estimation of Gases in Soft Waters," M. Robinet makes known the fact that petroleum, oil of lavender, oil of turpentine and benzine are capable of absorbing and holding in solution considerable quantities of air. When boiled in a proper apparatus they did, in fact, disengage the following proportions:Petroleum (by volume) Oil of lavender Benzine

Turpentine

"

6.8 per cent. 6.89 14'00 " • 24.18

On exposure to air afterwards, they again absorbed the same proportions. Petroleum and, probably, the analogous oils also dissolve carbonic acid. M. Buignet has determined the elastic force of the vapour of a specimen of petroleum, which he finds to be less than that of water. M. Jodin communicated some "Researches on the Modifications produced by Inactive Substances on the Rotatory Powers of Sugars," which seem, indeed, to be considerably modified in some instances by alcohol, and in all by lime. M. Marcé sent an account of some experiments, which prove that oil of wormwood, in doses of from 3 to 8 grammes, produces poisonous, but not fatal, effects. Trembling, stupor, and insensibility are produced with epileptic convulsions and stertorous breathing. The experiments throw some light on the nervous symptoms which follow the excessive use of absinthe. M. Barral sends to the Academy a note on a curious form of hailstone he observed in Paris on the afternoon of Easter Tuesday. The stones were of an absolutely conical form. We were passing through St. Paul's-churchyard about four o'clock on the same afternoon, and observed precisely the same phenomenon. We picked up at least a dozen of perfect cones, some of them three-quarters of an inch high and half an inch broad at the base. This form of hailstone, M. Barral says, has never before been noticed by meteorologists. Among the cones we noticed a few pyramidal stones which have been observed before. M. Barral observed traces of crystallisation in the structure of the stones he saw, and says they were very hard. Those we picked up were quite soft, and looked like moulded snow, and we remarked no trace of crystallisation. How were the cones produced?

MM. Davanne and Girard communicated a note "On some Theoretical and Practical Researches on the Formation of Positive Photographic Prints." We shall give in this place only the authors' explanation of what takes place in the case of albumenised paper on exposure to sun-light