that the student has successfully attacked some unknown problem, and added to the store of knowledge. The influence of science on the nation's industry has been recognised and insisted on by those who can make their voices heard. The country has at length awakened to the fact that something is wanting, and cries out for Technical Instruction. It is not afraid of spending money indeed, many well-meaning bodies are spending-and in some cases, I fear, wasting-money with a prodigal hand. And what, after all, is the great need? Speaking for the subject I know best, I say unhesitatingly that we want scientific chemists who can and will make discoveries; we want men trained, not only in what has been done, but taught how to set about winning new knowledge. The Universities, I urge, should teach the art of research. This is what is wanted, and this, as all experience shows, is what the Universities can do better than anyone else. And no exorbitant amount of time need be demanded for this purpose. If the student has learnt the elements of science at school, three years at most should suffice for the preliminary degree course. The graduate, armed with the necessary manipulative skill, would then start research work under proper guidance as the second and more valuable portion of his University training. And here the new research degree (by whatever name it may be called) may give us most valuable help. I hope that serious work will be demanded for it, and that the research course will become the recognised avenue to science fellowships and lectureships in the University. Two years would show what the man had in him. In that time either he would have proved himself no chemist, or he would have made some useful advance in our knowledge, and would have secured a testimonial of fitness such as no examination could confer. Five years in all-the minimum time now laid down for a medical qualification-would surely be not too much to ask for the chemist's training. No extra expense need be incurred to carry out this plan. Some of the college scholarships at present offered on entrance might be reserved for research studentships on graduation. These studentships should be the reward of the successful undergraduate career. On this point, which I have urged for many years, I am glad to find myself in entire agreement with the President of the Chemical Society. At Owens College our most successful endowment in Chemistry has been the Dalton Scholarship, awarded for a research done in the College laboratories. In the Victoria University we have lately founded scholarships for the encouragement of research, which are awarded on the results of the final examination in the several Honours Schools. The winners are entitled to hold their scholarships at any university at home or abroad where they can continue their special studies. I plead, then, for greater encouragement of chemical research in Oxford. Make it part of the normal course of training for everyone who wishes to be a chemist in fact as well as in name. Consider, not only the country's need, but the value of research itself as a mental training, as stimulating and strengthening the activities, as creating that sense of devotion and discipleship which becomes the tradition of every great school of learning. Lastly, let us own that we ourselves-the teachers here have been perhaps too critical, too much afraid of making mistakes, forgetting that the witty American's remark that he who never makes mistakes never makes anything has a far wider application in science than in politics. Only by practice and drill can we learn to collect our strength and swing it with precision into acts. Without that training, no matter how much faculty of seeing a man has, the step from knowing to doing' is rarely taken. There is nothing, I believe, in Oxford antagonistic to our cause. The genius of the place has not declared against scientific research; and if it be a true saying that men here imbibe a liberal education from the very air breathed by Locke and Berkeley, surely we also may draw scientific inspiration from this air, not only breathed, but first explained by Boyle and Hooke and Mayow. : The following Reports and Papers were read : 1. Report of the Committee on an International Standard for the 2. Report of the Committee on Electrolytic Methods of Quantitative Analysis.-See Reports, p. 160. 3. On the Proportions of Carbonic Acid in Air which are Extinctive to Flame, and which are Irrespirable. By FRANK CLOWES, D.Sc., Professor of Chemistry in the University College, Nottingham. It is generally maintained that a man cannot breathe air which contains sufficient carbon dioxide to extinguish a candle-flame. The correctness of this statement is of great importance to those who have occasion to work in an atmosphere which may contain large proportions of carbonic acid, such as that in a colliery or mine, or in a well-shaft. The careful determination of the proportion of carbonic acid in air which is just sufficient to extinguish flame has been made by the author, the method adopted differing essentially from the methods previously employed. Experiments by earlier investigators had shown very wide discrepancies. The author finds that the flames of candles, oil, paraffin, and alcohol are extinguished by air containing from 13 to 16 per cent. of carbonic acid. The flame of coal-gas, however, required the presence of at least 33 per cent. of the extinctive gas, and the flame of hydrogen was not extinguished until the amount of carbonic acid in the air reached 58 per cent. Taking 15 per cent. of carbonic acid as the proportion in air which is extinctive of ordinary portable illuminating flames, it is of interest to note that this percentage of the gas in air appears from the recent experiments of Mr. J. R. Wilson to be quite harmless when breathed. Mr. Wilson found that a rabbit which had breathed for an hour air containing 25 per cent. of carbonic acid was none the worse for its experience, but appeared at the end of the hour more lively than at the beginuing. Air containing 60 per cent. of carbonic acid, however, proved fatal to the rabbit after it had been breathed for a few minutes only. Unfortunately no intermediate proportions were experimented with. It is therefore apparently safe to say that air containing at least 10 per cent. of carbonic acid more than that required to extinguish a candle-flame can be breathed with impunity. Probably a much higher proportion of carbonic acid than this can be breathed. Dr. Angus Smith and many others fully support from experience the statement that a man can breathe and work in air containing more than sufficient carbonic acid to extinguish a flame. 2 The extraordinary vitality of the hydrogen-flame in the presence of high proportions of carbonic acid renders it valuable for maintaining the flame in a miner's safetylamp in foul air. The composite safety-lamp described by the author at the Nottingham Meeting of the British Association serves this purpose well. It can burn either an oil-flame or a hydrogen-flame or both together. When used for gas-testing, one of the flames only is used as occasion may require. But it has been found that when the lamp runs the risk of being carried into foul air, it is most advantageous to burn the hydrogen-flame alongside the illuminating oil-flame. A comparatively low proportion of carbonic acid extinguishes the oil-flame, and this would leave the miner in darkness and without the means of recovering his light, since the lamp may not be opened and relighted in the mine. But the hydrogen-flame continues burning in the presence of over 50 per cent. of carbonic 1 American Journ. Pharm., 50, No. 12. acid, and will rekindle the oil-wick after the foul air has been left or passed through. It is worthy of note that the proportion of carbonic acid which was extinctive of any particular flame was independent of the size of the flame. Further, it was noticed that the wick-fed flames gradually diminished in size as the proportion of carbonic acid in the air was increased; this was evidently due to the lowered temperature of the flame leading to a diminished supply of combus tible gas or vapour being produced from the combustible solid or liquid; the flame ultimately died because it was starved of fuel. The flames of gases fed from jets, on the other hand, increased in size as the proportion of carbonic acid in the air was increased. It appeared that the flame extended its surface in the air containing a diminished proportion of oxygen, in its endeavour to obtain the supply of oxygen necessary for its combustion. This expansion of the flame lowered its temperature ultimately below the kindling point of the gas, and the flame was therefore extinguished by being cooled. The extinctive proportions of carbonic acid for different flames was therefore determined by the amount of oxygen required for combustion, and by the extent to which the temperature of the flame in air surpassed the kindling point of the combustible gas or vapour. 4. On some Experiments with Free Hydroxylamine. The President of this section, Professor H. Dixon, has invited me to give some account of my researches concerning free hydroxylamine. In responding to this friendly request, I only propose to show you some of the properties of this substance by some experiments, for the time at my disposal forbids a detailed treatment of the subject; moreover a paper, containing the results of the investigation, has been published in extenso, in the 'Recueil des Travaux Chimiques des PaysBas.' In a few words I may remind you that the free base can be prepared in the following way. The hydrochloric acid salt of the base is dissolved in absolute methyl alcohol, the equivalent quantity of methylate of sodium is added, the common salt which precipitates is filtered off, and the solution of the free base concentrated by distillation at 100 or 200 mm. By fractionating the residue at the pressure of 20 mm., the pure free base passes over at 58° as a crystallised substance melting at 33°; it is of a high specific gravity (1:35), without odour, hygroscopic and volatile. The reason why the free hydroxylamine must be distilled at a low pressure is that the substance is pretty violently explosive, and that explosion occurs spontaneously at the temperature of 130°. Thus care must be taken never to heat the substance too strongly, for if heated at the ordinary pressure to 70° or 80°, an explosion may occur, the spontaneous decomposition raising the temperature. The hydroxylamine is an endothermous compound, and can be transformed totally into gaseous products, the two conditions which, as is known, characterise an explosive. I have produced an explosion in the following manner: 1 or 15 c.c. of the melted base were put into an ordinary open test-tube, with a thermometer in it; the tube stood in an ordinary beaker, which, heated by a burner, acted as an air-bath. When the temperature had reached 90°, the flame was withdrawn; the spontaneous decomposition was vigorous and the temperature rose to 130. Then a violent explosion took place, the glass apparatus was reduced to powder, the copper-gauze on which the vessel stood was torn to pieces, phenomena which prove that the explosion is of the same nature as that of high explosives. If one drop of the melted base in a tube is brought into a flame, a loud explosion is heard. The free base can burn in the air with a feeble yellowish flame. That hydroxylamine is a highly reducing agent is known since Lossen, about thirty years ago, discovered the salts of the base. It is obvious that the free base must show reducing properties in a much higher degree. On exposure to the air at the ordinary temperature it gradually attracts oxygen; one of the products of the oxidation is nitrous acid. When the free surface in contact with the air is extensive the oxidation is accompanied by a rise of temperature-for instance, when some filter paper or asbestos is moistened with the melted substance. A current of oxygen passing over the substance gives rise to the formation of fumes containing nitrous acid, the temperature rising at the same time. It is not surprising that oxidising agents act violently with the free base; thus, for instance, the solid permanganate of potassium, chromic acid, and some peroxides, in contact with some drops of the substance, produce inflammation. Powdered bichromate of potassium causes a sharp detonation; solid iodate of sodium and nitrate of silver are also reduced instantaneously. The action of anhydrous sulphate of copper is also very violent; the reduction of the salt may be accompanied by inflammation. Metallic sodium also acts violently, producing a flame. If the action is moderated by adding some dry ether, hydrogen is evolved and a white substance, NaONH,, is formed. This compound is a dangerous one because it explodes by contact with the air. The halogen acts vehemently with the free base; chlorine inflames it; bromine and iodine disappear immediately, producing the corresponding acids, water, and nitrous oxide. As to the solvent properties of the free base, these are nearly equal to those of water. It dissolves different salts, some of them, as for instance KI, in great quantity. Gaseous ammonia, introduced at 16° into the melted base, is dissolved rapidly and gives a solution containing 20 per cent. of the gas. In the same way the substance behaves like water with respec to other liquids; it is consequently only easily soluble in the alcohols and nearly insoluble in the ordinary organic liquids. Methyl and ethyl alcohol are miscible with the melted base in every proportion; these solutions, however, below the melting point of the base are supersaturated with respect to the solid compound. There exists, however, a difference between liquid hydroxylamine and water, the former not being miscible in all proportions with propyl alcohol. That hydroxylamine can occupy the place of the hydrate water in salts has been proved by Crismer, who has prepared the salts ZnCl2, 2NH,OH, BaCl, NH2OH, &c.; by means of dry ammonia Crismer has prepared the free base from these double-compounds. The presence of the hydroxyl group in hydroxylamine explains the analogies between this substance and water; the difference in their behaviour must be explained, at least partly, by the greater molecular weight of the former. Solid caustic soda is also very soluble in the melted base; care must be taken to keep it cool when adding the soda. This solution is much more liable to oxidation than the free base; exposed to the air the solution may spontaneously inflame. So we see that the presence of alkali (or rather of NaONH) increases in a high degree the liability to oxidation, the free base oxidising not so quickly as the solution of NaOH in it, while the solid NaONH, explodes in contact with the air. Although, as has been shown, free hydroxylamine is a strong reducing agent, it can be reduced itself by means of zinc dust. If this substance is moistened with the base (in an atmosphere of nitrogen), a pretty violent reaction occurs five or ten minutes later, and ammonia and zinc oxide are formed. 5. The Chemical Action of a New Bacterium in Milk. Up to the present time the chemical action of bacteria on sugar has received the largest share of attention, the alcoholic and acid fermentations offering themselves most readily for observation. In regard to the effect of bacteria on casein, it has generally been considered as sufficient to say that some bacteria seem to have a rennet-like action, whilst others have a peptonising effect. It was assumed that a certain class of bacteria have the peculiarity of producing an enzyme which curdles the milk under alkaline reaction, and afterwards producing another enzyme which dissolves the curd again. Such actions can be noticed if a milk is strongly heated and then left to itself. The author succeeded in isolating a bacterium, which had such an unusual effect on sterilised milk, that further studies appeared desirable. These investigations have been carried on by the author at the Hygienic Institute of Berlin. The special bacterium is a very short rod, scarcely lu1 long and 5μ in diameter: it shows rapid whirling motion, forms colourless liquid colonies on peptonegelatine, which is soon entirely liquefied; on agar a white slimy growth; on potatoes a smooth brown skin. No spores could be observed. The microbe has received the name Bacterium peptofaciens. A practical method of inoculating large quantities of milk with this bacterium was next described, the object being to obtain a new product out of milk in which all the casein is in a dissolved state, as it is well known that ordinary milk is not easily digested by many grown-up persons on account of the undissolved state of the casein. Milk which had been deprived of its cream by separators was used for this purpose. After incubation during eight days at 20° C. the further action of the bacterium was prevented by heating the milk. This killed the bacteria and caused coagulation of that part of the casein which had not been dissolved. A clear filtrate was obtained it had a yellow-reddish colour, an aromatic smell, and a taste reminding one of almonds. The results of a detailed chemical analysis were given. It was shown that more than one-half of the casein had been hydrated and formed into albumose and peptone. The various reactions of the dissolved protein substances were stated. A small amount of lactic acid was formed, and a very slight amount of acetic and butyric acids, these last two together coming only to 03 per cent. The bacterium does not produce any gaseous products, even after weeks of action. Sulphuretted hydrogen, indol, and skatol were not formed. The sulphur of the casein was still contained in the peptone. Ammonia was present in the form of salts, the amount of ammonia being equal to 07 per cent. Of tyrosin only the existence could be shown, the amount being too small to show crystals under the microscope. Reference was made to similar products generated during the ripening of cheese, which is entirely the action of microbes. 1 1μ=0·001 mm. |