DETEEMINATION OF ORGANISMS 63 



ization of methods for water examination (1904) 

 recommended the body-temperature count as a stand- 

 ard procedure. The American Committee on Standard 

 Methods in its 1905 Report did not recommend this 

 method even for alternative use. In its last report 

 (1912), however, it substituted the 37° for the 20° count, 

 which was dropped out entirely. As we have pointed 

 out in Chapter II, this course seems to us an unwise 

 one, and it was formally condemned at the meeting of 

 the Laboratory Section of the American Pubhc Health 

 Association in September, 191 2, by the passage of a vote 

 declaring that " ordinary routine examinations of 

 water for sanitary purposes, and in the control of 

 purification plants for the present, should include the 

 determination of the number of bacteria developing 

 at 20 degrees and 37 degrees." By this action the 

 body-temperature count is placed on a par with the 

 20-degree count as an integral part of sanitary bac- 

 teriological water examination, a course which has 

 been strongly urged in earlier editions of this book. 



The body-temperature count must, of course, be made 

 upon agar plates; but otherwise the procedure is 

 much the same as that already described for the routine 

 quantitative bacteriological examination in Chapter 

 II. A 1.5 per cent agar medium has generally been 

 used, but the Standard Methods Committee in its 

 recent report recommends only i per cent of agar. 

 Whipple (1913) points out that this i per cent agar 

 often gives trouble from the running together of the 

 colonies on the weaker medium. On the other hand, 

 a I per cent agar gives higher coimts than 1.5 per cent 



