CHEMICAL NEWS, May 3, 1862. The Theory of Spontaneous Generation. sufficient to furnish germs suitable to be developed in two or three days. It appears that the organic productions in the flasks are more various than if the contact with the air had been free, i.e., the organisms in the several flasks are different. This result might have been expected, for by limiting the rush of air and repeating it with different flasks, a small number of germs would be collected in a limited portion of air, and the growth of these germs would not be obstructed by other germs, more numerous or more vigorous or rapid in their growth, capable of monopolising the soil to the exclusion of those less vigorous or less rapid in growth. It was found that the number of negative results varied greatly with the atmospheric conditions, and that nothing was easier than to increase or diminish the relative proportion of flasks which gave birth to the organisms mentioned, or the number in which they were totally absent. In the cellars of the Observatory at Paris, so situated as to have very little change of temperature, and where the air was remarkably quiet, the proportionate number of flasks that were opened in that locality without producing any organisms was much greater than for the same number of flasks opened in the court-yard of the Observatory, where the air was constantly agitated. The explanation of this difference is obvious. Although the air of the cellars of the Observatory, nearly saturated with moisture, was more fitted for the production of the various kinds of mould and infusoria than the open air of the court-yard, yet the stillness of the air in the cellars allowed all ova and spores to be deposited by the force of gravity, and few or none remained floating in the air which rushed into the flasks opened in that locality. In proportion as more precautions were taken to avoid agitation of the air there was less appearance of organisation; and Pasteur concludes that if the flasks could be opened and closed in the cellars without the disturbance of the air caused by the entrance of the operator, there would be the same absence of vitality in the flasks filled with air from that locality as if they were filled with air exposed to a red heat. The following results were obtained by Pasteur with flasks opened in widely different localities: Sixty-three flasks were each one-third filled with a clear liquid obtained by filtering water mingled with the scum of beer, all solid matter being removed by the process of filtering. This liquid is known to be very susceptible of change, for exposure to ordinary air for two or three days is sufficient to give birth to small infusoria or a variety of mucedines. The fluid was boiled in all the flasks, and they were hermetically sealed as in the previous experiments. Twenty of the flasks thus prepared were opened and closed in the country far from any habitation, at the foot of those heights which form the first plateau of the Jura mountains. Twenty other flasks were filled with air upon one of the mountains of the Jura, 850 mètres (2789 feet) above the level of the sea. Another series of twenty flasks were carried to Montanvert, near the Mer de Glace, to an elevation of 2000 metres (6562 feet), where they were filled with air and hermetically sealed like the others. Of the twenty flasks opened in the level country, six developed organic productions. Among the twenty flasks opened upon the plateau of the Jura, only five developed organisms; but of the twenty flasks filled with air at Montanvert, when a strong wind was blowing from the gorges of the Glacier des Bois, one only produced organisms. 24I These experiments show that the air from elevated localities is remarkably free from those germs which give origin to organic products. In collecting air for these experiments the following precautions were adopted to avoid as far as possible the intervention of dust carried by the operator or deposited on the outside of the flask or other implements required in performing the experiments. The elongated neck of the flask was first heated in the flame of a lamp, and a scratch was made upon the glass with a file. The flask was then raised above the head with the end of the neck turned towards the wind, and the point was broken off with long iron forceps, the branches of which had previously passed through flame to destroy any dust adhering to their surface, so that it might not remain to be driven into the flask by the sudden rush of air when the point of the flask was broken. Great pains were taken lest the agitation of the liquid in the flasks during transit might exert some influence unfavourable to the development of infusoria or mucedines. The following results are therefore without objection, and they show the entire difference between the air of the plain or of elevations and that of inhabited places. Pasteur's first experiment at the Glacier des Bois was interrupted by a circumstance which has not been foreseen. He had taken to close the points of the flasks, after they were filled with air, an eolipile lamp fed with alcohol. The whiteness and glare of the ice, in the light of the sun, was so great that it was impossible to see the jet of alcohol flame, and as it was agitated by the wind it could not be directed upon the glass with sufficient steadiness to melt the point and hermetically seal the flask. As no means were at hand to render the flame visible, the flask could not be sealed, and there remained chances of error by the admixture of other powders. The three flasks which had been opened were therefore taken to the small village of Montanvert, and sealed at his lodgings the next morning, after they had been exposed all night to the dust of the chambers where he slept. Of these three flasks only two produced either infusoria or mould. Since the number of flasks altered in this experiment is greater than that in those which followed (the twenty flasks previously noticed), Pasteur concludes that the agitation of the liquid during the journey had no influence upon the development of germs. It therefore appears to be satisfactorily demonstrated: 1. That the air of inhabited places contains a greater relative number of fruitful germs than the air of uninhabited regions. 2. That the ordinary air contains only here and there, without any continuity, the condition of the first existence of generations sometimes considered spontaneous. Here there are germs and there there are none. 3. There are few or many, according to the localities. Rain diminishes the number; but after a succession of fine days they are more numerous. Where the atmosphere has been for a long time quiet germs are wanting, and putrefaction does not take place as in ordinary cir calcined air, and passed it into a flask of putrescible | milk from the richer districts is slightly purer than that fluid by the process detailed in the former part of this paper. In every experiment of this kind after two days an abundant growth of organic products appeared. The same experiments were repeated with the same liquids, with no change of manipulation, with the same kind of mercury, except that the mercury was first heated to destroy the germs it contained, and no growths whatever appeared in the flasks. From all these experiments Pasteur concludes that powders suspended in the air are the exclusive origin, the first and necessary condition of life in infusions in putrescible bodies and in liquids capable of undergoing fermentation. It is easy to collect and observe with the microscope atmospheric dust, among which may always be found a great number of organised corpuscles which the experienced naturalist will distinguish as the germs of inferior organisms. | [Some infusoria are not more thanth of an inch in diameter, and if we suppose that the ova of infusoria and the spores of minute fungi are no more than onetenth part the linear dimensions of the parent organism, there must be an incalculable amount of germs no larger han 240000th or 100000th of an inch in diameter. Since, according to Sullivant and Wormley, vision with the most powerful microscope is limited to objects of aboutth of an inch, we need not be surprised if infusoria and other organisms appear in putrescible liquids in far greater numbers than the germs in atmospheric dust visible by the aid of the microscope would lead us to expect.-TR.] Pasteur proposes to continue these investigations, and expresses the hope that the way may thus be opened for a successful investigation of the origin of different diseases.-American Journal of Science, Vol. xxxii. No. 94 On the Quality of the Milk Sold in the Poor and other Districts of Dublin, by WILLIAM J. WOUFOR and SYDNEY R. PONTIFEX, Students in the Laboratory of the Museum of Irish Industry, Dublin. (ABSTRACT.) A PAPER on the above subject was read at the meeting of the Royal Dublin Society, held on Monday evening, April 14. The investigation was undertaken for the purpose of ascertaining the quality of the milk sold in the poor districts of Dublin; but as the quality of the milk can be greatly altered by the kind and quality of the food upon which the cows are fed, samples of milk from the more wealthy districts were analysed in order to ascertain whether the poor were worse served than their more affluent neighbours. Twenty samples of milk from as many different dairies were examined; thirteen of the samples were purchased in very poor districts, and seven were obtained from richer districts of the city. The examination proved that the only adulteration was water. The numerous published analyses of milk of known purity made by various chemists prove that when cows are fed with proper food the quantity of water in the milk is constant, although the proportions of the various substances forming the fixed constituents is variable; the normal quantity of water in pure milk is 87:35 per cent.; this quantity is never exceeded beyond a few tenths per cent. more or less. The average quantity of water in the thirteen samples from the poor districts of Dublin, examined by the authors of this paper, was 90:28 per cent., and the average quantity in the better districts was 89'4 per cent. Although, taken collectively, the from the poor districts, yet, when taken singly, the analyses show that the best milk-in fact, perfectly pure milk-was obtained from one of the very poorest districts (Sherriff-street) in the city, and that the rich district of Rathmines is supplied with as poor a milk as the poor street, Brabazon-street. It will be seen from the analyses that three out of the twenty milks examined were pure, and that the remaining seventeen were more or less adulterated. According to the published Report of the Lancet Sanitary Commission, out of the twenty-three London milks examined by them,— 1st. Twelve were genuine. 3rd. That the adulteration consisted in all cases of water, the per-centages of which varied from ten to fifty per cent., or one-half the article. It will be seen from the mean of the analyses of the seventeen adulterated samples of Dublin milk, that the amount of water added is 3.5 per cent.; in no case did it exceed 5.6 per cent.; so that the Dublin people are supplied with a much purer article than the inhabitants of London; and it may be remarked that the districts selected by the Lancet Commission appear to be all in the better parts of London. The authors described the methods they adopted for the estimation of the different substances, and they pointed out that specific gravity of the milk, whether determined by the instruments called lactometers, or by the still more accurate plan of the specific gravity bottle, is no certain indication of the purity of the milk. Two analyses of the different milks were made. The following are the means of the two analyses, with the names of the streets in which the milk was procured. The authors give in their paper also the names of the vendors of the milks. The investigation was carried out in the laboratory of the Museum of Irish Industry, under the direction of Professor Galloway. Specific gravity. Rathmines Road. Total amount of organic matter Butter Caseine Albumen Sugar 2.695 9'298 *720 90'005 100*023 1025°35 9*004 2.217 2.632 4'17 Caseine and albumen Sugar Ash Water Total amount of organic matter Butter Caseine and albumen Sugar Ash Water 5*500 10.989 835 87.662 99*486 1023'34 99'990 stores of food in the soil with that vigour which is needful in order to appropriate them without hindrance. The fact that winter wheat is more delicate and fastidious in its infancy than most other crops, is perhaps the main reason why it does not succeed well on many good lands, and why it cannot be continuously produced from the same soil, year after year. It is a matter of experience that wheat requires a rather firm seed-bed ; beans, oats, and mangold-wurzel approach wheat in their requirements, while barley, peas, and turnips are best suited in a light tilth. On the other hand, climate, 7921 weather, and tillage so influence the character of the soil, that even on light lands wheat may find all the conditions of its growth. The bed which is produced by inverting a clover sod, and allowing it to consolidate by time and rains, or by passing a heavy roller over it, is eminently adapted to wheat, even on a rather light soil. The fact that in the cases given above from Stoeck99892 hardt, clover succeeded when sown with lucerne or esparsette, would indicate that possibly the condition of the seed-bed was the cause of failure. 1023.28 1023 74 These and other facts, which might be adduced to almost any extent, indicate sufficiently that chemical analysis alone, even if we admit its full nicety and accuracy, can at the best furnish us with a knowledge of but a few of many conditions which must co-operate in profitable agricultural production, and, as a consequence, 99'940 its part in guiding the farmer is but very subordinate. Taking into the account its evident uncertainty and clumsiness when applied to estimating the minute quantities which affect vegetable growth, the part it can play becomes still more subordinate-we hesitate not to say, insignificant. On Soil-Analysis, by Professor S. W. JOHNSON, of Yale College. (Concluded from page 227.) TWELVE or thirteen years ago, Dr. Anderson, in his capacity of Chemist to the Highland and Agricultural Society of Scotland, had occasion to investigate two soils which had become "clover-sick," and he caused them, together with similar adjacent soils which still produced clover, to be most minutely analysed. Without reproducing his figures, which may be found in the Transactions of the Highland and Agricultural Society for 1849-51, p. 204, we will merely quote some of the remarks which accompany the analyses :-"The results of these analyses are certainly of an unexpected character, and appear to me to indicate that, in this instance, the failure of the clover cannot have been dependent upon the chemical constitution of the soil. In both cases the results of the analyses of each pair do not present a greater difference than would be obtained from the analyses of two portions of soil from different parts of any field." As we write, a fragment from a scientific journal brings to our notice a discovery which, if real, strengthens our views in an unexpected manner. It is well known that iodine is so immensely diluted in sea-water-the soil of marine-plants-that none of our tests, though they are among the most delicate, serve to detect it directly, and it is doubtful if it has been detected even in the highly concentrated mother liquors which remain after separating the crystallisable salts, yet the fuci find and accumulate it, and we must grant that it is present there for them, in sufficient quantity. Again, Prince Salm Horstmar several years since, in his admirable researches on the influence of the individual mineral ingredients of plants on the development of oats and barley, found that he could not by any possibility exclude chlorine from his experimental plants. His soils and pots, the salts and water he fed his plants with were so purified that he could not detect this element in them, and yet he invariably discovered it in the ashes of the plants. So, too, he found titanic acid in the produce grown on the most carefully purified soils. Now, it is mentioned in the CHEMICAL NEWS that he finds a few hundredths of lithium are indispensable to the ripening of barley. This element Bunsen has but recently shown to be everywhere distributed, yet it has been hitherto entirely unnoticed in all soil- and plantanalyses, because of its occurrence in almost infinitesimal quantity. In the present year, Stoeckhardt (Chemischer Ackersmann, No, ii., 1861, p. 85) has published an account of several "clover-sick" soils from Schlanstaedt, which reveal to analysis a greater content of every nutritive mineral ingredients, both soluble in water and in acids, than exists in another soil from Frankenstein which produces clover and wheat as well. What proves beyond a doubt that the inability of these soils to yield clover depends upon something besides their chemical constitution, is the fact that lucerne and esparsette still flourish upon them admirably; and further, clover itself, if sown It must be well borne in mind that Agriculture herself with one of these last mentioned crops, succeeds very-so-called Practice-is able of her own resources to well. judge somewhat of the value of soils, is able to know if a soil be fertile or poor, is able to pronounce upon its adaptation to crops, and can to a certain extent decide what is a good manure for this or that field. A great truth in agriculture is this: Each kind of agricultural plant requires that its seeds be surrounded with certain conditions in order that they may germinate readily and healthfully, so that when the mother cotyledons are exhausted, the young plants shall attack the We are free to assert that the knowledge which is now to be gathered from experience, is able, in ninety-nine CHEMICAL NEWS, On Sulphur Determinations in Coal, Coke, &c. cases out of one hundred, to give a more truthful verdict as to the capacity of a soil, than any amount of analysis, chemical, mechanical, or otherwise, can do. We would give more for the opinion of an old intelligent farmer than for that of the most skilled chemist in most questions connected with farming. Doubtless the farmer would make some blunders from which chemistry might save him, but the chemist would be likely to do more violence to agriculture than the farmer would to chemistry. By these statements, which may, but should not, surprise some of our scientific friends, we merely intend to express an opinion as to the present relative position towards agriculture of those who regard the art from a chemical, and those who see it from an experimental point of view. If any one has fuller and more inspiring notions of the importance of science in its applications to agriculture than we have, we desire to sit at his feet and share the higher afflatus. But our inspiration, if it be of the sort that works enduring benefit, must be based on clear ideas of the directions in which advance is possible, and on a full perception of the difficulties that lie before us, and the means of overcoming them. We have great faith that chemistry and that chemical analysis have done and are to do a work for agriculture, that shall lay that venerable art under everlasting obligations to the youthful science. But not by soil-analysis alone or mainly is this to be achieved. We do not assert that soil-analysis is worthless-we believe that the probabilities of its uselessness in direct application to practice are so great that we would rarely base any operations on it alone, and yet it may, in many cases, promote science and give us data for conclusions that are of practical use. But for these purposes it must form part of a system of observations and trials, must be a step in some research, must stand not as the index to a barren fact, but as the revelator of fruitful ideas. We hold that soil-analysis long ago played out the part which Dr. Peter would have it perform. In the hands of Sprengel it was fertile with new truth, but it must henceforth be a tool for occasional use, and not an engine of discovery. With our advance in knowledge there must be an advance in methods of finding out the unknown. Soil-analysis was indeed a means of insight into the secrets of vegetable growth, but it carried with it the measure of its limit. What we call telescopes do not enable us to see the end! To study the soil in the hope of benefiting agriculture, we must regard all its relations to the plant. We must examine it not merely from those points of view which theoretical chemistry suggests, but especially from those which a knowledge of practical agriculture furnishes. This is becoming more and more the habit of agricultural chemists, and the results are of the happiest kind. Let us remember what the illustrious Nestor of Agricultural Science, Boussingault, has said as the summing up of his protracted experience and study : "At an epoch not far distant it was believed that strict connection existed between the composition and the quality of arable soil. Numerous analyses shortly modified this opinion as too positive. The sagacious Schübler even sought to prove in a research that has become classic, that the fertility of a soil depends more upon its physical properties, its state of aggregation, power of absorption, &c., than upon its chemical constitution." "The physical properties, in my opinion, do not enable us, more than the chemical composition, to pronounce 245 upon the degree of fertility of the soil. To decide this point with some measure of certainty, it is indispensable to have recourse to direct observation; it is necessary to cultivate a plant in the soil, and ascertain with what vigour it developes there: the analysis of the plant afterwards intervenes usefully, to indicate the kind and quantity of the elements that have been assimilated."— ("De la Terre Végétale considerée dans ses Effets sur la Vegetation," page 283 of "Agronomie, Chimie Agricole et Physiologie, Tome premier, 1860.") There has been much progress made in our knowledge of the soil during the last ten years. This advance has not consisted in revealing to us the presence of new elements (lithia perhaps excepted), nor in fixing with any more certainty the quantitative limits which separate barrenness from fertility, it has not shown what is the composition of a silurian or a sub-carboniferous, a drift or a tertiary soil, it has not defined the soil adapted to wheat or that productive of clover, it has not indicated the manures which this or that soil needs; but content with the fact that all soils which naturally support vegetation contain the elements of vegetation, it has sought to ascertain in what forms these elements are assimilable, how they may be made available, what changes or reactions in the soil affect its productiveness; how fertilisers act indirectly (their influence often having no relation to any supposable direct action), how the soil affects the life of the plant otherwise than by feeding it, &c. We are approaching, in fact, by slow degrees to an understanding of the physiological significance of the soil, a grand result to which chemistry and physics co-operate. We trust that in future people will not less but more appreciate the value of science in its practical and especially its agricultural bearings; that here, as in Germany, France, and England, the labours of those who seek to unite practice with science may be fostered and sustained. But to this end scientific men must be cautious that in endeavouring to help, however honestly and laboriously they may work, they do not hinder.American Journal of Science. On Sulphur Determinations in Coal, Coke, &c., by In this short article I would draw attention to the fact, The following experiments were done to test the accuracy of the two processes,-viz., first, fusion with a mixture of nitrate of potash, chloride of sodium, and carbonate of potash; and secondly, boiling in nitric acid. To give the nitric acid process every chance, I used a coke containing very little sulphur: 1. I fused one gramme of this coke with the following mixture in a platinum crucible until all the carbon had burnt away : 16 grammes of chloride of sodium 8 |