CHEMISTRY. 



89 



new compound8 is much greater than that of 

 the original hsBmatein and brazilein, and the 

 colors are much faster. 



Prof. F. W. Clarke and Mary E. Owens have 

 obtained a number of new substances from the 

 action of potassium cyanate upon the com- 

 pounds of platinum. With platinum tetra- 

 chloride they obtained a buff-yellow precipi- 

 tate soluble in water, but completely insoluble 

 in alcohol, the aqueous solution of which de- 

 composes on boiling, and to which analysis gave 

 the novel formula, K 2 PtCl 6 (CNO)H 2 O. With 

 the green salt of Magnus, PtN" 2 H 6 Cj, new com- 

 pounds were formed, apparently of great com- 

 plexity. The hot aqueous solution, concentrated 

 to the crystallizing point, deposited pale-yellow 

 needles, containing potassium, ammonia, water, 

 and carbon, with 43*93 per cent of platinum. 

 From the mother-liquor beautiful brown crys- 

 tals were obtained, in which were found am- 

 monia, platinum, and chlorine. Strychnia 

 chloro-platinate with potassium sulpho-cyanate 

 gave a blood-red solution which, after cooling, 

 deposited a brilliant red crystalline precipitate, 

 2(C 2 iH 22 N 2 O 2 )H 2 PtCy 8 S6 the strychnia salt 

 analogous to the potassium sulpho-cyanoplati- 

 nate. 



Ogier has obtained a new oxychloride of 

 sulphur by heating to 250 in sealed tubes a 

 mixture of equal weights of S 2 C1 2 and SO 2 C1 2 . 

 Jts composition is expressed by the formula 

 (SaOOlOa + S0 2 + S. It is a dark-red liquid of 

 density 1*656, and of a repulsive odor, recalling 

 that of sulphur chloride, and is decomposed by 

 water and by heat of 100. 



ATOMIC WEIGHTS. Mr. James Blake, of 

 Calistoga, Cal., has determined the atomic 

 weight of beryllium and its true position 

 among the elements, by the application of 

 the rule that the intensity of the action of 

 different substances upon organisms increases 

 with their atomic weight. Introducing the 

 salts of beryllium to the blood of living ani- 

 mals, he found that the reactions caused by 

 them were the same as those caused by the 

 salts of alumina and ferric oxide, and strik- 

 ingly different from those caused by the salts 

 of the magnesium group. The metal is there- 

 fore placed in the aluminum group ; and this 

 determines its atomic weight as 13'65, and the 

 formula for its oxide Be 2 3 , in accordance with 

 the determinations of Nilson and Pettersson. 

 Roscoe has redetermined the atomic weight 

 of carbon by the method employed by Dumas 

 and Stas, which consists in the direct combus- 

 tion of the diamond. The mean of six separate 

 experiments, taking the atomic weight of ox- 

 ygen as 15-96, was 11-9708. 



NEW PROCESSES. The tests for the detection 

 of oleomargarine and of impurities in butter 

 depend upon chemical analysis and upon the 

 determination of specific gravity. Two pro- 

 cesses of chemical analysis by saponifying the 

 fat of the butter are used at the Municipal 

 Laboratory in Paris. In the first process, the 

 clear fat saponified with potassic hydrate (three 



or four grammes of fat to one or two grammes 

 of hydrate) is mixed with 50 c.c. of alcohol, after 

 which the soap, provided the solution formed 

 is perfectly clear, is decomposed with weak 

 sulphuric acid, and the insoluble fat- acids are 

 collected and weighed. The quantity of fat- 

 acids thus obtained is in butter usually 86-5 to 

 87'5 per cent, and sometimes as high as 88 

 per cent; in animal fats from tallow the per- 

 centage of insoluble fat-acids is 95|. The dif- 

 ference about 8 per cent is attributed to 

 the absence in tallow of volatile and soluble 

 fat-acids which exist in butter. In the other 

 process, the result is obtained volumetrically, 

 by estimating the quantity of potassa used in 

 saponifying the fat. One gramme of butter re- 

 quires from 225 to 232*4 c.c. of potassa solu- 

 tion, while one gramme of tallow or other fat of 

 the same nature requires from 195 to 197 c.c. 

 of the same potassa solution. M. Charles 

 Girard, of the Municipal Laboratory, considers 

 as adulterated any butter requiring, for saponi- 

 fication, less than 221-5 c.c. of the potassa solu- 

 tion. 



The test by determination of the specific 

 gravity, as employed by Messrs. Leune and 

 Harburet, consists in placing the clear melted 

 fat in a cylinder heated by the vapor escaping 

 from a boiling water-bath, but no part of 

 which is in the boiling water. By heating in 

 this way, the temperature of the melted fat is 

 kept at about 93 0., or about 199 Fahr. To 

 determine the density of this fat, an areometer 

 is placed in it, so graduated that in butter it 

 will sink to the lowest mark of the scale, while 

 in oleomargarine it will stand at the highest 

 point. The intervening space in the scale is 

 divided into ten equal parts, each one of which 

 corresponds to one tenth of oleomargarine 

 mixed with butter. This instrument is relied 

 upon to give correct results to within ten per 

 cent. Mr. P. Casainajor, from the results of 

 his experiments to ascertain the actual specific 

 gravity of the two substances, has derived 

 another very simple test with alcohol. It con- 

 sists in finding the grade of alcohol in which 

 the substance will remain at equilibrium in 

 whatever part of the liquid it is placed. Mr. 

 Casamajor found that this was, for butter, al- 

 cohol of 53*7 per cent; for oleomargarine, of 

 59-2 per cent, at 15 C., or 59 Fahr. The fat 

 may be melted in a little spoon or scoop and 

 dropped upon the alcohol, care being taken to 

 have the drop free from air-bubbles. If alcohol 

 at 56 per cent the medium between the two 

 grades specified above is taken, a globule of 

 melted butter will sink in it to the bottom, 

 while a globule of oleomargarine will remain 

 at the top, both being still warm and liquid. 

 Afterward, if the alcohol is raised to about 30 

 C., or 86 Fahr., the butter will become solid, 

 while the oleomargarine may still remain 

 liquid. Then the butter will rise to the top 

 of the alcohol. If the alcohol is then kept for 

 a few minutes at 15 C., the oleomargarine 

 will become opaque and remain at the top, 



