136 ELEMENTS OF WATER BACTERIOLOGY 



methods of procedure by bodies of authoritative posi- 

 tion, both in England and America. In 1904 an 

 English Committee, appointed to consider the Stand- 

 ardization of Methods for the Bacterioscopic Examina- 

 tion of Water, presented a series of obligatory tests 

 and optional tests; and in 1905 the Committee on 

 Standard Methods of Water Analysis of the American 

 Public Health Association drew up a set of diagnostic 

 characters for B. colL The latter corresponded in 

 general with the plan developed by the Massachusetts 

 State Board of Health (Massachusetts State Board of 

 Health, 1899) and long in use at the Massachusetts 

 Institute of Technology, and involved the determina- 

 tion of morphology, motility, fermentation of dex- 

 trose broth, coagulation of milk, production of indol 

 and reduction of nitrates. The English standard pro- 

 cedure corresponded quite closely to this (Committee 

 appointed to consider the Standardization of Methods 

 for the Bacterioscopic Examination of Water, 1904), 

 although it differed from the American method in cer- 

 tain respects. 



Since these standards were formulated 8 years ago 

 their artificial nature has been made more and more 

 manifest to those who have used them. A still more 

 fundamental question, however, has pressed itself 

 upon the practical analyst. Each lactose bile presump- 

 tive test involves the use of a single tube of medium 

 and the work is complete in 48 hours. The " com- 

 plete " test as used in America required the use of 

 seven different media and took 9 days to complete, 

 since the gelatin subculture must be incubated for 



