Deoembee 16, 1004.] 



SCIENCE. 



841 



AMERICAN CHEMICAL SOCIETY. 

 NEW YORK SECTION. 



A REGULAR meeting- of the section was held 

 at the Chemists' Club, Friday evening, No- 

 vember 11. 



Dr. Hugo Schweitzer introduced the follow- 

 ing resolution, which was seconded by Mr. 

 T. J. Parker : 



The speedy introduction of the metric system 

 of weights and measures by appropriate laws is 

 most desirable in order to rid our country of a 

 most illogical and cumbersome system, which is 

 one of the greatest obstacles to tlie development 

 of our export trade, and in order to place our 

 •country on a parity with other great manufactur- 

 ing countries. 



After some discussion by Messrs. Peckham, 

 Schweitzer and Parker, the resolution was 

 adopted without dissenting vote. 



The regular program was then taken up and 

 the following- papers read : 

 The Determination of Ammonia in Milk. H. 



C. Sherman and W. N. Berg. 



This paper summarized the work thus far 

 accomplished, the preliminary results of which 

 were presented at the Providence meeting in 

 June, 1904. 



The Boussingault-ShafPer method (slightly 

 modified) in which the sample is mixed with 

 methyl alcohol, made alkaline with sodium 

 ■carbonate and distilled under diminished pres- 

 sure, had been found to be sufficiently delicate 

 for the determination of ammonia in milk 

 where the amount is often less than 0.001 per 

 cent. 



With, an alkalinity corresponding to 0.5 per 

 cent, sodium carbonate in the mixture of milk 

 and alcohol, a cleavage of ammonia from 

 organic matter appeared to be brought about 

 by this process in the case of stale, but not 

 fresh milk. 



If the boiling mixture be saturated with 

 sodium chloride, to reduce the hydrolytie dis- 

 sociation of the alkali, this cleavage is largely, 

 if not entirely, prevented. The results thus 

 obtained are believed to represent very closely 

 the true amount of preformed ammonia in the 

 samples, while the amount of ' cleavage am- 

 monia ' yielded by a sample, when submitted 

 to this process without the addition of salt, 



appears to be of value as an indication of the 

 condition of the proteid matter. 



Methods in which the milk is made alkaline 

 and boiled under atmospheric pressure to ex- 

 pel the ammonia, gave high results even when 

 the dilution of the alkali was very great. At- 

 tempts to correct the amount of ammonia 

 given off in a second period of distillation 

 were not satisfactory. 



Preliminary experiments indicate that while 

 milk tends to develop both acidity and am- 

 monia on standing, there is no necessary con- 

 nection between the two, since either may in- 

 crease rapidly while the other increases slowly, 

 if at all. 



Report of Committee on Methods for the De- 

 termination of Zinc. G. C. Stone. Uni- 

 formity of Technical Zinc Analyses. 

 Early in 1903 the committee sent out three 

 samples of zinc ore : ' A ' a pure blende from 

 Joplin containing about 2 per cent, each of 

 iron and lead and 0.3 per cent, of cadmium; 

 ' B ' an ore from New Jersey containing con- 

 siderable amounts of manganese and iron; 

 ' C ' a Colorado blende containing about 14 per 

 cent, of lead and 7 per cent, of copper. These 

 were analyzed by forty-two chemists who re- 

 ported from 56.97 to 59.79 zinc and 2.10 to 

 3.26 iron in 'A'; from 12.20 to 39.22 zinc 

 and 18.04 to 21.92 iron in 'B'; and from 

 28.90 to 38.86 zinc and 8.40 to 15.00 iron in 

 ' C As the results were so disgraceful the 

 committee have classified the methods in eight 

 groups and discussed them and the results at 

 considerable length. They find that the dis- 

 crepancies are largely due to the attempt to 

 apply to ores to which they are totally un- 

 suited quick methods that were devised for 

 special cases. For the bad work the com- 

 mittee think the poor instruction given in 

 many of the schools is largely to blame. The 

 only method that gave imiformly good results 

 is that described by Waring {Jour. Amer. 

 Chem. Soc, January, 1904, p. 9) ; the only 

 reason that they do not recommend its gen- 

 eral adoption is that it has only been tried 

 by a very small number of analysts. In con- 

 elusion they ask for volunteers to test some 

 of the methods more fully. 



