Contributions to the Chemical Bacteriology of Sewage. 455 



r olf(R.) Astronomische Mittheilungen. LXXVII. 8vo. Zurich 

 1891. . The Author. 



'hototype Portrait of Horace Benedict de Saussure. 



M. Henri de Saussure 



April 23, 1891. 

 5ir WILLIAM THOMSON, D.C.L., LL.D., President, in the Chair. 



The Presents received were laid on the table, and thanks ordered 

 them. 



The following Papers were read : 



"Contributions to the Chemical Bacteriology of Sewage." 

 By Sir HENRY E. ROSCOE, F.R.S., D.C.L., LL.D., and 

 JOSEPH LUNT, B.Sc., F.C.S. Received April 23, 1891. 



(Abstract.) 



The present research contains the results of experiments on the 

 emical and bacteriological examination of sewage micro-organisms, 

 ade with the object, in the first place, of ascertaining what species 

 are there present, and, in the second, of determining some of their 

 emical characteristics. 



The authors have isolated from crude sewage, by methods which 

 are fully described, a number of organisms which may serve as 

 typical examples of those usually present in this material. Some of 

 these have already been described, whilst others are believed to be 



Iw organisms. 



The microscopic and macroscopic appearances of the organisms and 

 their pure cultures have been carefully recorded by means of photo- 

 graphs, which give in a permanent form their morphological characters 

 and the plate- and tube-cultivations in their most characteristic stages 

 of growth. This method of illustration the authors consider to be of 

 much importance, as bacteriological descriptions of organisms are 

 frequently of little value for the want of accurate representations of 



microscopic preparations and pure cultures. 



The experiments described were undertaken with the object of 

 studying the reactions of sewage organisms from a chemical point of 

 iew, and of gaining information as to the rationale, both chemical 



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