292 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND PHYSICS. 
supplied to London. He says that the two chief objects to be 
kept in view are “the discovery of the evidence of past pollution 
by organic matter and the quantitative determination of | 
or actual organic impurity.” With reference to the first point, he 
ives his opinion that the presence of nitrogen in the forms 0 
nitrates, nitrites and ammonia in potable waters, in quantity above 
that which can be derived from rain, is reasonably safe and trust- 
worthy evidence of the previous pollution of that water by animal 
matters. As to the second, he shows that, of the four processes 
proposed for determining organic constituents, known as the ign 
ion, the permanganate, the albuminoid-ammonia and the combus- 
tion methods, the two first are quite useless; of the third he con- 
waters for sanitary purposes. The combustion process, Le ak 
devised by himself nine years ago, he believes to be reliable. He 
mitted to investig® 
now be conducted in any laboratory and wit 1976. 
diture of time and labor.—J. Ch. Soc., elxii, 825, at g. F. B 
2. On the Absorption of Nitrogen by Organic oa by of 
BertHe.or has found that pure nitrogen gas 18 absor 
eros cement 
