Presence of Certain Diatoms in a Town Water Sujoply. 483 



TABLE E.— Chemical Composition of Lucerne Ensilage. 

 (Weiske, etc., Bied. Centr., 1884, pp. 464-469). 



Siloed Close. Slightly Pressed. Not Pressed. 



TABLE F.— Baeley and Malt. 



(Bungener and Fries, Bied. Centr., 1884, pp. 406-409.) 



Nitrogen. 



XLIIT. Note on the Presence of Certain Diatoms in a Town 

 Water Supply. By W. IvisoN Macadam, Esq., F.C.S., 

 F.I.C, etc., Lecturer on Chemistry, School of Medicine, 

 and Professor of Chemistry, New Veterinary College, 

 Edinburgh. 



(Read 15th April 1885.) 



The presence of these minute forms of vegetable life in 

 fresh and salt waters has been long recognised, but the 

 number of specimens to be obtained from any one sample of 

 water has generally been very small. In the case to which 

 I beg leave to direct your attention, the water is of excellent 

 quality for domestic use, is soft in character, and contains 

 only very minute proportions of ammonia. The chlorine is 

 merely a trace, and nitrogen, as nitrates or nitrites, entirely 

 absent. As, however, the water is collected from running 

 streams, it is liable to contain in mechanical suspension more 

 VOL. VIII. 2 H 



