previous experience, that if the tube were removed, there would be a difficulty in reinserting it, and that in the critical state of the patient, he might be destroyed if any such difficulty should present itself; the other gentlemen felt the same; therefore I requested the opinion of Mr. Fergusson. Before this gentleman arrived, the patient had again become better, had fallen asleep, and awoke sensible, and stated that he felt more comfortable. However, Mr. Fergusson, on carefully examining the patient, considered that it was necessary to remove the tube. It was therefore taken out, and on examination was found to be partially blocked by viscid mucus. Fortunately another was inserted without much difficulty, care being taken to keep the edges of the opening in the trachea apart by means of blunt hooks. The breathing now became quiet, and the countenance lost its livid appearance; but another source of danger presented itself; for within the last few hours excessive swelling of the upper part of the neck had come on, and an erysipelatous redness was diffusing itself over the chest below the wound. Large quantities of wine, beef-tea, and chloric ether were given, and the patient was most assiduously watched. A stick of nitrate of silver was drawn over the margin of the inflamed skin. The calomel was omitted.

14th. The patient had some nice sleep during the right. The countenance is more natural; the erysipelas has not spread beyond the line of the nitrate of silver; there is a great deal of irritating cough, and a considerable discharge of mucus from the wound. At mid-day, the patient had a sudden attack of difficulty of breathing, which rendered it necessary to remove the tube; it was cleaned and re-inserted, upon which the breathing became calm, and the irritation was lessened. Beef-tea, wine, and other stimulants are freely given.

15th. After taking a dose of laudanum last night, he had some sleep; and this morning he feels better. Pulse 100, full, and soft; respirations easy, eighteen in the minute; tube cleaned and re-inserted.

16th. Not so well to-day; there have been violent paroxysms of cough, and an immense discharge of purulent matter from the wound; he consequently passed a bad night, and is irritable and depressed. The erysipelas has again begun to spread over the chest, and has reached the right axilla. The tube was removed from the trachea, and left out for a short time, and the irritating cough ceased; tube cleaned and re-inserted; opium, wine, and beef-tea are freely given.

17th. Slept pretty well occasionally during the night, but the paroxysms of cough have been frequent and violent, and the discharge of matter from the wound is larger in quantity, thinner, and slightly tinged with blood. Tube to be removed

and kept out, and the edges of the wound to be kept apart by two bent probes, tied behind the neck. Erysipelas stopped by the nitrate of silver.

18th. Passed a better night; breathes freely through the opening without the tube; on closing it with the finger, great distress is produced, and he can only take a few inspirations by the natural passage; pulse 80.

19th. I was called to this patient in the middle of the night, and found him in a distressing state of dyspnoea, indeed, as bad as before the operation. On examination, I found that the opening in the trachea was almost entirely blocked up by thick mucus. This was cleared away; the patient was immediately relieved, and he has, for the first time, this day taken some solid food. He is assiduously watched night and day.

20th. Again I was hastily summoned, late last evening, as another attack of dyspnoea had come on. On my arrival, I found the patient better, but ascertained that he had been nearly suffocated, and that he would probably have died, had not a relation, who was a medical man, been in the house, and cleared the wound, which had become blocked up. It being evidently unsafe to dispense with the tube, I re-introduced it, and gave a large dose of laudanum. The patient's mind was at once tranquillised.

22nd. He has been progressing favourably since the tube was re-introduced, but there has been considerable tracheal irritation, and, therefore, it was left out the whole of yesterday; but to-day, the tracheal irritation, which had considerably lessened when the tube was removed, again came on; consequently, I re-inserted it, and the irritation ceased at once.

Yesterday he sat up for an hour. As there is evidently considerable thickening about the larynx, hyd. cum cretâ is given in doses of three grains every four hours.

25th.. Has been progressing favourably; is getting up his strength; sits up three or four hours daily; mouth is affected by mercury; can breathe more freely by the natural passage; the tube is cleaned and re-inserted every day.

April 8. It is now a month since the operation; the patient is so much better, that he breathes pretty comfortably for at least ten minutes together when the opening is closed; but the tube cannot be dispensed with, as the noisy sound in the breathing indicates considerable narrowing at the entrance of the larynx. Counterirritation, by means of blisters and croton oil, has been employed, and the patient, being weak and nervous, takes quinine thrice daily.

20th. As regards general health, this patient may be deemed convalescent, as he has regained his strength and flesh to a considerable extent; but the remains of the disease in the larynx still persist, and render necessary the use of the tube; for, although he can breathe a considerable time together with the opening closed, the respirations are noisy, and soon become laborious. In order to permit of more easy breathing, a tube has been constructed, with a very large opening on the convex surface, and, at the same time, a stopper has been made to fit in the anterior opening; by this means the patient can close it at will, and the air passes more readily in and out of the lungs than it would if there was simply a tube in the larynx, without an opening on its upper surface. He exercises his breathing in this way for some time together, and gets more confidence. We are keeping up a little counter-irritation over the throat.

May 1. This patient has been enabled to take carriage-exercise continually, and has been doing well until the last few days, when he has been thrown back in consequence of a domestic misfortune. The tube is worn with great comfort. There is occasionally a considerable secretion of thick pellets of mucus from the trachea. Dr. Thompson has carefully inquired into the condition of the larynx by means of the stethoscope, and is of opinion, from the noisy sound heard during respiration over the glottis, that there is still considerable narrowing at the entrance of the tube; consequently it has been determined to put the patient fully under the influence of mercury again; accordingly he is taking it twice daily.

25th. He was brought fully under the influence of mercury, and the gums were kept sore for some length of time; but the disease in the larynx has not been removed by it, only somewhat lessened. The mercurialisation had the effect of weakening the patient very much; it also was followed by severe periosteal pains. The patient has, during the last month, been enabled to attend to his business. A respirator is worn over the tube, and his neckerchief is so adjusted, that its presence cannot be detected by ordinary observers. He has now retired into the country to spend the summer, and it is hoped, that, in course of time, the remains of the thickening, which undoubtedly exists in the larynx, may gradually be removed, and thus permit the entire disuse of the tube, which could not at present be dispensed with. I must not omit to state, that a very careful examination of the lungs has been made on several occasions, and that there is not any evidence of disease there. The chest expands well, even when the artificial opening is closed.—Med. Times and Gazette, July 9, 1853, p. 34.

43.-ON THE PATHOLOGY OF PHTHISIS.

By DR. CORNELIUS BLACK.

[The following is an abstract of Dr. Black's reasearches into the pathology of pulmonary consumption:]

Assuming that the first substantive deflection from the standard of perfect health is in a deficient vitality of formative elements of the blood, the origin, manifestation, and progress of pulmonary consumption are briefly enunciated in the following propositions:

1. That pulmonary consumption observes three stages.

a. The stage of Local Predisposition.

b. The stage of Deposition.

c. The stage of Germination.

2. That the stage of local predisposition is characterised by more or less excess

of blood in the pulmonary capillaries of the affected part; that it corresponds to the first pathological condition of bronchitis and of pulmonary cellulitis; that the degree and extent of this local predisposition vary considerably; and that the resulting phenomena bear a proportionate ratio in point of severity and appreciability.

3. That the stage of deposition is attended by increased exudation from the pulmonary capillaries; that this exudation is incapable of entering into structural relation with the pulmonary tissues; that it leads to a more or less rapid thickening of the basement structure of the bronchio-pulmonary membrane; that it likewise accumulates in the intervascular and intercellular spaces; and that the pulmonary tissue is thereby more or less consolidated.

4. That the first appreciable sign of the stage of germination is a shedding of the epithelium of the affected portions of lung; that this epithelium does not attain perfect mucus-cell development; that in cases in which the deposition has been slow, it (the epithelium) is more granular than are properly developed mucus-cells; but that the epithelium is still more granular in cases of rapid turbercular deposition.

5. That the epithelium thus shed is not, in progressive tubercular disease, replaced; that, so long as a particle of healthy basement structure exists, the nuclear points of that structure attempt to replace such lost epithelium; but that this properly vitalised basement structure failing before such attempt at the restoration of the epithelium has succeeded, the latter is now cast off in the form of basement patches, which show, here and there, a germinating point.

6. That the tubercular deposit undergoes, during germination, more or less development into cells; that this growth constitutes the "softening" of authors; that it takes place contemporaneously throughout each isolated and individual mass of tubercle; that it, therefore, does not first commence at either the centre or circumference of the exudation; but that it proceeds more rapidly at the circumference, because at this point the conditions of cell growth are more abundant than at the centre. At the circumference, therefore, plastic and pus-cells abound; at the centre exudation cells.

7. That in the cheesy-looking portions of tuberculous sputum there are very frequently, indeed, portions of nerve tubes, and occasionally of lymphatic vessels and of the minute bronchi; that, in other portions of such sputum, plates of cholesterine, the colouring matter of the bile, cystine, and urate of ammonia are occasionally seen by the microscope.

8. That the microscopic appearance of the nerve tubes thus expelled shows that the nerves do not terminate in loops upon the pulmonary mucous membrane, but in bulbous expansions, to be hereafter depicted.

9. That the foregoing observations show pulmonary consumption to consist in anormal nutrition, and to be essentially analogous, in its steps, to inflammation; but that the term "inflammation" would be inapplicable to it, inasmuch as it fails to explain the cause of the deficient vitality of the blood-plasma, which constitutes the essential nature of tubercle.-Association Med. Journal, Sept. 9, 1853, p. 799.

DISEASES OF THE ORGANS OF DIGESTION.

44.-ON THE CHEMISTRY OF DIGESTION.

By DR. G. E. DAY.

·

[Our readers can hardly fail to appreciate the following elaborate review of Professors BIDDER and SCHMIDT's work on The Digestive Fluids and Metamorphosis of Tissue,' and of Dr. CARPENTER'S Food and the Digestive Process,' by Dr. G. E. DAY, the esteemed professor of medicine at St. Andrew's. Of the different secretions employed in the digestive process, that of the salivary glands comes naturally to be considered first. The principal use of this would appear to be to promote the conversion of the amylacea into dextrine, sugar, and lactic acid, and thus promote the absorption of this class of foods.]

The first point we shall notice is the time required for the metamorphosis of starch by human saliva (the mixed secretion). If we take a fresh decoction of starch, prepared with distilled water, and proved by Trommer's test to be free from sugar, and

if we mix it with an equal quantity of fresh saliva, and agitate the mixture, it will instantly lose its viscid character, and become thin and watery; on testing a small quantity of it for starch, we find that iodine no longer induces the well-known reaction, while, on the other hand, the rapid reduction of oxide of copper (in Trommer's test) affords indisputable evidence of the presence of sugar.

The almost instantaneous induction of this actiou is a point which must not be overlooked, in considering the question whether this is a special property of the saliva, or whether it is shared by other animal fluids. There can be no doubt, as we shall presently show, that in this respect the pancreatic and the intestinal juices exactly coincide with the saliva; but when we find stress laid upon the circumstance that many organic substances-as, for instance, nasal mucus, pieces of kidney, putrefying serum, &c.-produce similar changes in eight or twelve hours, at 100° or upwards, we may recollect that at such a temperature, and after so long an interval, changes may be spontaneously set up in a solution of starch. There are, however, a number of animal substances which occasion the appearance of sugar in a solution of starch, in so short a period as altogether to exclude, in such cases, the suspicion of spontaneous metamorphosis; but the action induced by the saliva is incomparably more rapid even than that of any of these substances.

[We may ask, are the secretions of the three sets of salivary glands of equal importance in producing the final result?]

The following are the two principal conclusions at which Bidder and Schmidt have arrived in connection with these points:

1. They agree with Bernard in regarding the parotids as glandes aquipares; in short, as yielding a secretion which is unquestionably intended to moisten and saturate the dry food, but whose principal object is connected with the general metamorphosis of the fluids within the body, and which is devoid of any marked action on starch.

2. By the union of the submaxillary secretion and that of the buccal mucous membrane, there is formed that peculiar ferment which almost instantaneously converts starch into sugar. This active principle is not contained in the cells or other solid particles suspended in the saliva; for the filtered fluid exhibits an undiminished force; and, indeed, this property is not destroyed when, by the addition of a little alcohol, we precipitate the mucus and (entangled in it) these solid particles.

There is still considerable obscurity and diversity of opinion regarding the question, whether the action of the saliva on starch is continued in the stomach. Jacubowitsch, Frerichs, and Bence Jones believe the metamorphic process is continued in the stomach, and Lehmann and Carpenter support this view, while the experiments of Bidder and Schmidt lead to an opposite result.

[It would appear from these experiments that starch should be rapidly converted iuto sugar in the stomach; but in animals, where it has been introduced artificially, the result has afforded a conclusive demonstration that no conversion into sugar takes place in this organ.]

Now, seeing, in the first place, that the formation of sugar commences in the mouth immediately upon the starch coming in contact with the saliva, and further bearing in mind that no sugar can be usually detected in the stomach, it follows that one of two things must occur-either that the newly-formed sugar is at once absorbed, or that it is converted into lactic acid, and in this form mixes with and is lost in the gastric juice. In the latter case, we must ascribe to the gastric mucous membrane the power of instantaneously converting sugar into lactic acid-a power which, as we learn by experiments, is possessed neither by the stomachs of herbivora or carnivora ; in the former case, we can only say, that so rapid an absorption is perhaps the least improbable mode of explanation.

We are bound to remark, that the above opinion of Bidder and Schmidt, regarding the absence of sugar in the gastric contents of animals fed upon starch, has not met with universal acceptation. It is true that it is in accordance with views previously expressed by Blondlot, and by Bouchardat and Sandras, but it is opposed to the results obtained by Frerichs (who "in at least fifty experiments" constantly found sugar in the filtered contents of the stomachs of men, carnivorous and omnivorous nammalia, and birds), and to those of Jacubowitsch.

The secretion of the glandular apparatus imbedded in and forming the chief bulk of the mucous coat of the stomach next claims our attention. Many of our best.

recent observers (amongst whom we may especially mention Hübbenet, a pupil of Bidder and Schmidt's) believe that two perfectly distinct secretions are found in the stomach-namely, the true gastric juice and gastric mucus. Almost all observers since Beaumont have agreed in describing the former as a clear aqueous or only slightly viscid fluid, with a strong acid reaction, and devoid of morphological elements -that is to say, of essential morphological elements; for on a microscopic examination, a few solid particles, consisting partly of unchanged cells of the gastric glands, partly of the nuclei of these cells, and partly of fine molecular matter, which is produced by the disintegration of these elements, may usually be observed; it is only secreted during the period when digestion is actually going on, and it is this fluid alone which possesses any true digestive power. All that is known of the latter (the mucus) is, that it accumulates in the empty stomach, that it is neutral (unless when slightly alkaline from the commixture of saliva), and that it exerts no solvent action on the protein compounds. Frerichs, however, whose views on the Chemistry of Digestion are entitled to the highest respect, holds a different view, and maintains that at the commencement of each act of digestion the round cells in the interior of the glands escape in excessive quantities, and form a stratum of about a line in thickness, which has been hitherto regarded as mucus, and which either invests the interior of the stomach, or surrounds the contents in the form of a white membrane, the latter being especially the case when dry food is taken. The gastric cells become gradually disintegrated during the continuance of the digestive process, and thus afford a continuous source of pepsin or ferment. The digestive act being accomplished, the gastric glands collapse, and in that state no nuclei or cells, and only a few scattered granules, escape from them. During abstinence from food, the morphological elements are again perfectly formed, and the tubes become filled with cells, which probably in very prolonged fasting again become disintegrated.

There are two points in connexion with the secretions of the gastric mucous membrane to which Kölliker has directed special attention, and which we will now lay in a condensed form before our readers.

The first is, that in many of the mammalia the gastric mucous membrane is covered with a more or less thick coat of mucus during digestion. This fact was originally noticed by Eberle in the stomachs of rabbits, and he clearly regarded the mucus as essential to digestion.

[The gastric mucus can scarcely be regarded as essential to the digestive process, except that it may possibly exert a peculiar influence in certain parts of the stomach. The gastric juice is acid, unless there be an excess of mucus, when it may be neutral, or when a large quantity of saliva is swallowed, when it may be alkaline. It contains a free acid, a highly nitrogenised matter, termed 'pepsin,' or, more recently styled, 'ferment substance.' It is perfectly astonishing how enormous have been the labours of these indefatigable labourers, MM. Bidder and Schmidt. They have recorded no less than 45 series of experimental inquiries, embracing 140 individual experiments.]

Their experiments lead to the following conclusions:

The admixture of saliva with the gastric juice is of no service, in so far as the solution of albuminons bodies is concerned. It appears, that in experiments with gastric juice containing saliva, the number expressing the dissolved per centage of dry albumen was not so high as in corresponding experiments (both sets of experi ments being made within the stomachs of dogs) when the saliva was excluded. Whilst in the latter the averages of nine experiments of two hours', nine of four hours', and nine of six hours' duration were 29, 62, and 76 per cent., in the former they were only 26, 45, and 65 per cent. This difference is unquestionably depend ent upon the partial neutralisation of the free acid of the gastric juice by the saliva. Both classes of experiments agree in showing that the acid gastric juice possesses a specific and peculiar power of dissolving coagulated albumen; and if this solution proceeds with more rapidity in the stomach than externally to the organism, the reason is, that in the former the albumen is kept in constant motion, and is being always brought into contact with fresh quantities of gastric juice. Several of Bidder and Schmidt's experiments show, that provided a sufficient quantity of pepsin be present, the digestive power of the gastric juice varies in a direct ratio with the amount of free acid that it contains. That the solvent power of the gastric juice is not solely due to the presence of hydro-chloric acid is, however, evident from