performed in a large porcelain basin, using plenty of water, gently rocking and rotating the mixture, and allowing it to rest at intervals; the lighter portions are then sucked up by means of a pipette, this being continued until nothing but the copper-coloured crystals are left. The largest quantity which has been separated in this way is equal to '032 per cent. Ferro-manganese containing different percentages of manganese and of different makes has been examined, and, with the exception of spiegeleisen containing 11 per per cent. of manganese, they have all been found to contain this remarkable compound. As the quantities available for examination were small, with the exception of determining the specific gravity and the amount of the titanium only qualitative tests have been applied. In different specimens the specific gravity has been found to vary between 41 and 5.1, and the titanium from 60.5 to 79.8 per cent. These latter determinations include a small proportion of iron, which I have always found to be present; this is also the case with crystals separated from an old blast-furnace 'bear. After several days' heating with hydrochloric acid there is 15 per cent. iron retained, and probably this is the cause of the crystals being slightly but distinctly magnetic. Attention is specially directed to the fact that much valuable information with regard to the condition of the foreign elements may be obtained by decomposing large quantities of the alloys with suitable reagents, and separating the substances of different specific gravity from the residue. In doing this it is pointed out that there is great danger of decomposing the compounds originally present, and forming new ones as a result of the reaction which takes place between the reagent and the various substances present. Such a method as is indicated in this paper is recommended to be used in conjunction with the examination of etched specimens, which of themselves do little beyond revealing changes of structure induced by different modes of manipulation and varying temperatures. The insufficiency of etched specimens to give us information with regard to the condition of impurities is evident from the fact that, being opaque, so nearly alike in colour, and in such minute and uniformly distributed particles, they escape observation. SATURDAY, SEPTEMBER 16. The Section did not meet. MONDAY, SEPTEMBER 18. The following Reports and Papers were read:- 1. Interim Report on the History of Chemistry. 2. Report on the Wave-length Tables of the Spectra of the Elements. See Reports, p. 387. 3. Interim Report on the Bibliography of Spectroscopy. 4. Report on the Bibliography of Solution-See Reports, p. 372. 5. Report on Solution.-See Reports, p. 438. 6. A Discussion on the Present Position of Bacteriology, more especially in its relation to Chemical Science, was opened by Professor PERCY F. FRANKLAND, F.R.S. Professor FRANKLAND's paper was ordered to be printed in extenso among the Reports.-See Reports, p. 441. 7. Remarks on the Chemistry of Bacteria. By R. WARINGTON, F.R.S. 8. On Fermentation in the Leather Industry. By J. T. WOOD. The science of bacteriology touches upon the leather industry in the following important points: 1. Putrefaction. 2. The Soaks. 3. Changes in lime liquors. 4. Bating or 'Puring.' 5. Drenching. 6. Fermentation of tan liquors. The author only gave a short résumé of our present knowledge of the 'drenching' process, as this closely resembles ordinary fermentations. Skins from the bate after washing are placed in vats containing an infusion of bran in water (0·4 to 1 per cent. of bran) at a temperature of 30° to 35° C. This ferments vigorously for eighteen to twenty-four hours with evolution of considerable quantities of gas and the formation of weak organic acids, which have a slight swelling action on the skin, cleanse the pores, and make it in a fit condition to receive the tannin. On examination with a high power of the microscope the liquid is found to be swarming with active bacteria. They are mostly in the form of pairs or dumb-bells, each cell 0·75μ × 1.25μ; some form chains. I described 1 a method by which the organism causing the fermentation was separated, as it refused to grow in ordinary nutrient gelatine, and lately, in conjunction with Mr. W. H. Willcox, B.Sc., have made a complete examination of the products of the actual fermentation as it takes place in the works, previous to carrying out a similar research with the pure ferment. A is from a vat containing no skins, one to two days. B from a vat containing skins, two to three days. C from a vat containing skins, three to four days. The HS is present only in small quantities (1 to 2 per cent.). The principal acids found were acetic acid and lactic acid, accompanied by small quantities of formic acid and butyric acid. The following table shows the quantities found in an experimental drench per 1,000 c.c.: Journ. Soc. Chem. Ind., ix. 27. We find in actual work that the quantity of acid produced varies from one to three grms. per litre. We found that an unorganised ferment, 'cerealin,' changes the starch of the bran into glucoses and dextrin; the bacteria then ferment the glucoses, splitting them up into the gases and acids already mentioned. B. furfuris has no action on the cellulose of the bran, nor on the skins, as some bacteria in the bate have; in every case where the skin is attacked it is putrefactive or gelatine liquefying bacteria introduced from the bate, or in specially favourable circumstances (hot, sultry weather) developing from germs always present in the atmosphere. The gases evolved have only a mechanical action on the skin, floating and distending them, and so enabling them better to take up the acids. In carrying out this work we discovered a delicate test for lactic acid. The presence of lactic acid was shown in the following manner :-10 c.c. of the liquid were placed in a small distilling flask along with 2 c.c. strong H2SO, and about 05 grm. potassium chromate in a little water. This was distilled and the vapours received in a test tube surrounded by cold water; on adding magenta solution discolourised by SO, to the liquid in the test tube a red colour was produced by the aldehyde formed from the lactic acid; aldehyde was also recognised by its smell. We find this an exceedingly delicate test for lactic acid, and as far as we know it is quite new in this form. For 10 c.c. of liquid to be examined we find 2 c.c. strong H,SO, and 1 grm. of potassium chromate to be the best proportions. Formic, acetic, propionic, butyric, valerianic, succinic, malic, tartaric, and citric acids do not give the reaction. In conclusion, there are no doubt other organisms capable of fermenting a bran infusion in a somewhat similar way, and the work of isolating and separately examining their life-history and products yet remains to be done." 9. On some Ferments derived from Diseased Pears. From diseased pears the author has isolated, among other micro-organisms, three which possess morphological and chemical interest. (1) A yeast (Saccharomyces viscosus) which is characterised by forming small cells of an average length of 0·003 mm. and white, strongly viscid growths upon solid nutrient media. It brings about no alcoholic fermentation of the betterknown sugars, but inverts cane sugar. It can propagate either by budding or by endogenous division. (2) A bacterial organism (Ascococcus luteus) forming yellow growths upon nutrient gelatine. Growths of two types have been obtained, one showing ascococci, the other only rods. It is an acid ferment of dextrose and mannitol. (3) A bacterial organism forming white growths upon nutrient gelatine. Two types of growth have been obtained upon nutrient media, one in which micrococci and rods predominate, another in which the tendency to form ascococci is strongly marked. These two types are represented by widely differing macroscopic cultures upon solid media. Both forms behave as lævo-lactic ferments towards dextrose and mannitol. The organism is an inactive-lactic ferment of rhamnose, but after such action still retains its power of decomposing dextrose into lavo-lactic acid. 10. On the Action of Permanganate of Potassium on Sodium Thiosulphate and Sulphate. By G. E. BROWN and Dr. W. W. J. NICOL. 11. On the Application of Sodium Peroxide to Water Analysis. Now that sodium peroxide can be obtained commercially, its use in analysis seems desirable. W. Hempel has already shown that it is a useful oxidising agent for the detection of chromium and manganese, and that it forms a very convenient reagent for opening up tungsten minerals and for effecting the decomposition of titanic iron ores. Since the commercial sodium peroxide is free from sulphur, it can also be used quantitatively for estimating the sulphur in sulphides. It occurred to us that an alkaline oxidising agent of this character, if used as a substitute for alkaline permanganate in water analysis, might throw some light upon the character of the organic nitrogen in waters. Hitherto either methods for determining the total nitrogen-e.g., Frankland's and Kjeldahl's, or Wanklyn's well-known process in which only a portion of the nitrogen present in the organic matter is discovered-have been employed. In this latter process very different quantities of ammonia are obtained from the different classes of nitrogenous organic bodies. Only when the nitrogen is present as some simple amido- compound like urea, aspartic acid, or leucine does this process yield the whole of the nitrogen present. Preusse and Tiemann have shown in their review of the various processes for determining organic substances in water that no reliance can be placed upon this process for estimating the absolute quantity of nitrogen in many substances, and that, therefore, when used as a method of water analysis the quantities of ammonia obtained are only relatively true for waters of the same type. A comparison of the quantities of ammonia evolved from a water when treated with alkaline permanganate and with sodium peroxide might therefore possibly afford a means of differentiating the nitrogenous constituents. With this purpose in view we have compared in the ordinary course of analysis the amounts of ammonia given off under these two treatments. In one case when using one grm. of sodium peroxide per half litre of water, the total ammonia evolved was equal to 0-027 part per 100,000, while with alkaline permanganate 0.050 part per 100,000 was obtained. On repeating this experiment with the same water and under similar conditions, 0.026 part per 100,000 was yielded by the peroxide and 0·048 by the permanganate. The addition of a further quantity of the sodium peroxide and further distilling did not increase the quantity of ammonia produced, and it was therefore evident that the sodium peroxide had failed to break down the organic nitrogenous substances present to the same extent as had the alkaline permanganate. In fact, we have since found it possible to obtain a fresh quantity of ammonia from a water after treatment with sodium peroxide by the addition of the alkaline permanganate. The following table gives the results obtained in parts per 100,000 with four samples of water: From these figures it will be seen that the sodium peroxide in no case oxidises the organic matter present to the same extent as does the permanganate. The peroxide seems to liberate a portion of the nitrogen which is included in that set free by the alkaline permanganate, as the total ammonia obtained by the action of Zeit. anorg. Chem., 3, 193. 2 Berichte, 12, 1906. the peroxide, followed by permanganate, is in most cases about equal to that obtained when the water is distilled with alkaline permanganate alone. There appears to be no ratio between the quantities of ammonia evolved by the two reagents, and therefore the nitrogenous organic matter present in waters might be divided into two classes, viz., that which is oxidised by the sodium peroxide and that which resists such treatment. The results obtained by Wanklyn's process, as compared with the total nitrogen present in a water, also show a differentiation in the organic nitrogen substances present in waters, but this knowledge has hitherto not been of any value owing to the complex nature of the problem. Further experiments can alone decide whether the limited oxidation of the nitrogenous matter in waters will throw any fresh light on the condition of these organic constituents of water. We have, however, noticed that in some cases a water which has been partially oxidised by the peroxide yields the remainder of its ammonia to the alkaline permanganate with much greater rapidity than when the water has not been so treated. We suggest that the explanation of this phenomenon may be due to the presence in waters of organic nitrogenous substances which, when partially oxidised, are then in a condition to be completely broken up by the stronger reagent. This result has been obtained with waters containing fresh sewage, but we hope by taking solutions containing nitrogenous compounds of known constitution to confirm this suggestion, and to show that in this reagent we have an oxidising agent which will be useful in establishing the constitution of the nitrogen in complex organic substances. TUESDAY, SEPTEMBER 19. The following Reports and Papers were read: 1. Report on Isomeric Naphthaline Derivatives.-See Reports, p. 381. 2. On the Application of Electrolysis to Qualitative Analysis. By CHARLES A. KOHN, Ph.D., B.Sc., Lecturer on Organic Chemistry, University College, Liverpool. Since the publication of C. Bloxam's papers on 'The Application of Electrolysis to the Detection of Poisonous Metals in Mixtures of Organic Matters little has been done to apply this method of analysis to qualitative investigations, despite the fact that Classen and his pupils, together with E. F. Smith and others, have made rapid advances in electrolytic methods of quantitative analysis. Many of these later methods offer special attraction for qualitative work, especially in cases of medical and of medico-legal inquiry. They are not supposed to supersede in any way the ordinary methods of qualitative analysis, but to serve as a final and crucial means of identification for the more important mineral poisons. The applicability of the methods for the detection of antimony, mercury, lead, copper, and cadmium has been examined. The method originally devised by Bloxam for the detection of arsenic has been more recently elaborated by Wolff, who has succeeded in detecting 0.00001 grm. of arsenious acid electrolytically. Antimony. The method employed is that used in the quantitative estimation by electrolysis, a method devised by Classen, and which ensures a complete separation from antimony and tin. The precipitated sulphide is dissolved in potassium sulphide, any polysulphides present oxidised with hydrogen peroxide, and the solution electrolysed with a current of 1.5-2.0 c.c. of electrolytic gas per minute (10-436 c.c. at 0° and 760 mm. =1 ampère), a small circular piece of platinum 1 cm. in diameter being employed as the cathode. The deposited metal can be confirmed for by evaporating a little ammonium sulphide on the foil. One part of J. Chem. Soc., 13, pp. 12 and 338. |