CHEMISTRY. (MISCELLANEOUS.) 



119 



mation properly conducted in suitable and well- 

 drained soils can cause no risk to the public 

 health. The results of the bacteriological ex- 

 amination of the various soils goes to corrob- 

 orate the results arrived at by chemical means. 

 No pathogenic organisms were found in grave- 

 yard soils ; and although the number of bacteria 

 present was greater than at similar depths in 

 virgin soil, it was not so great as one might have 

 expected. There was, moreover, a very marked 

 and sudden fall in the number of organisms in 

 the soil below the layer containing the coffins. 

 So that, as Reimers has pointed out, the 

 " ground- water " region is practically free from 

 bacteria. 



Frank, and afterward Schloesing and Laurent, 

 showed that soil containing bacteria and alga? 

 can fix free nitrogen in large quantities, but 

 their experiments did not decide whether algae 

 alone are capable of doing this. In order to 

 answer this question Kossowitsch has estimated 

 the amount of nitrogen present in a nutritive 

 soil before and after the growth of pure cultures 

 of alga? Cystococcus and Stichococcus. In neither 

 case was any sensible increase of nitrogen de- 

 tected, so that it appears that neither of these 

 algae alone has the power of fixing free nitrogen. 

 Cystococcus, even when mixed with pure cultures 

 of the bacteria which enable the Leguminosce to 

 assimilate free nitrogen, was found powerless in 

 this direction : whereas a mixture of soil bacteria 

 and Cystococcus, which also contained a small 

 amount of other algae, had the power of fixing 

 . free nitrogen to a large extent. Kossowitsch also 

 describes a number of experiments with hetero- 

 geneous mixtures of algaa and bacteria, and shows 

 how in each case the capability of fixing free 

 nitrogen is greatly increased by the addition of 

 dextrose to the nutritive substratum. From 

 this, and also from the fact that such mixtures 

 of algae and bacteria which are capable of fixing 

 free nitrogen when exposed to light can not be 

 shown to assimilate it in the dark, he concludes 

 that although it has not been proved in any case 

 that algae by themselves possess the power of 

 fixing free nitrogen, yet they are in a symbolic 

 relationship with the nitrogen-fixing bacteria ; 

 and he regards it as probable that these latter 

 draw on the assimilation products of the algae 

 to supply the carbon they require in growth. 



The science of bacteriology touches upon the 

 leather industry, according to J. T. Wood, in 

 the following important points : Putrefaction, 

 the soaks, changes in lime liquors, bating or 

 " puring," drenching, and fermentation of tan 

 liquors. The activity of bacteria in the " drench- 

 ing " process is described by the author. Skins 

 from the bate after washing are placed in a vat 

 containing an infusion of bran in water at a 

 temperature of from 30 to 35 C. This fer- 

 ments vigorously for from eighteen to twenty- 

 four hours, with evolution of considerable quan- 

 tities 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 con- 

 dition to receive the tannin. On examination 

 with a high power of the microscope the liquid 

 is found to be swarming with active bacteria. 

 In the operation an unorganized ferment, " ce- 

 realin," changes the starch of the bran into 

 glucoses and dextrin. The bacteria then fer- 



ment the glucoses, splitting them up with evo- 

 lution of gases and formation of acids. The 

 bacteria causing the fermentation have no action 

 on the cellulose of the bran or on the skins as 

 some bacteria in the bate have. In every case 

 where the skin is attacked it is by putrefactive 

 or gelatin-liquefying bacteria introduced from 

 the bate, or in specially favorable circumstances 

 developing from germs always present in the at- 

 mosphere. The gases evolved have only a me- 

 chanical action on the skins, by which they float 

 and distend them, and so enable them better to 

 take up the acids. There are, no doubt, other 

 organisms capable of fermenting a bran infusion 

 in a somewhat similar way, and the work of iso- 

 lating them and separately examining their life 

 history and products yet remains to be done. 



A new bacterium is described by Dr. Bernth- 

 stein as occurring in milk, which peptonizes the 

 casein, forming a soluble compound, and ren- 

 dering the milk transparent and more readily 

 digested. 



Miscellaneous. The characters, composi- 

 tion, and even the number of the proteids con- 

 tained in the wheat kernel or derived from it are 

 the subject of very conflicting statements on the 

 part of those who have examined these bodies. 

 The results of an investigation undertaken in 

 hope of clearing away some of this confusion are 

 published by T. B. Osborne and C. G. Voorhees. 

 After a long series of experiments they find 

 that the proteids contained in the wheat kernel 

 are : A globulin belonging to the class of vegeta- 

 ble vitellins, soluble in saline solutions, precipi- 

 tated from them by dilution and also by satura- 

 tion with magnesium sulphate or ammonium 

 sulphate, but not by saturation with sodium 

 chloride; an albumin, coagulating at 52, which 

 differs from animal albumin in being precipi- 

 tated on saturating its solution with sodium 

 chloride or with magnesium sulphate, but not 

 precipitated on completely removing salts by 

 dialysis in distilled water : a proteose, precipi- 

 tated, after removal of the globulin and the al- 

 bumin, by saturating the solution with sodium 

 chloride, only adding 20 per cent, of sodium 

 chloride and acidifying with acetic acid ; glia- 

 din, called by other authors plant gelatin, gluten 

 fibrin, mucenin, or insoluble phytalbumose, solu- 

 ble in distilled water to opalescent solutions, in- 

 soluble in absolute alcohol, but soluble in alcohols 

 of below 90 per cent, strength ; glutenin, a pro- 

 teid insoluble in water, saline solutions, and di- 

 lute alcohol, which forms the remainder of the 

 proteids of the wheat kernel, generally about 

 4 to 4-5 per cent, of the seed. Wheat gluten is 

 composed of gliadin and glutenin. The gliadin 

 with water forms a sticky medium, which by the 

 presence of salts is prevented from becoming 

 wholly soluble. This sodium binds together the 

 parts of the flour and renders the dough and 

 gluten tough and coherent. The glutenin im- 

 parts solidity to the gluten, evidently forming a 

 nucleus to which the gliadin adheres and from 

 which it is consequently not washed away by 

 water. Gliadin and sta'rch mixed in the pro- 

 portion of 1 to 10 form a dough, but yield no 

 gluten, the gliadin being washed away with the 

 starch. The flour freed from gliadin gives no 

 gluten, there being no binding material to hold 

 the particles together so that they may be 



