SPOROGENES TEST. 3 
tion. Savage (12), who was among the first to apply the test for 
this purpose, and who has studied the test probably more than any 
one else, realized its limitations. He states that the test does not 
show so close an agreement with the cleanliness of farm conditions 
as does the estimation of B. coli. On the whole, however, he thought 
that the sporogenes test might be of considerable value in estimating 
pollution, especially in market milk. Eitchie (11) concluded from 
his results that the sporogenes test was of little value. He obtained 
no correlation between the number of positive reactions and farm 
conditions. Barthel (1) was of the opinion that there never was a 
direct relation between the hygienic quality of milk and the presence 
of strict anaerobes. On the other hand, Weinzirl and Veldee (15) 
have used the test as a means of determining the manurial pollution 
of milk and believe it to be of distinct value. 
There is nothing new about the sporogenes test so far as its general 
application is concerned. It has been known for a long time, but it 
has not been given a thorough trial under controlled conditions of 
production. From past results the test gives promise of being too 
valuable to discard, yet it is too uncertain at present to use without 
knowing its limitations. 
It is the purpose of this paper to present some results obtained 
with the sporogenes test on milk produced ' under controlled con- 
ditions. 
THE SAVAGE METHOD. 
Savage (12) first examined 1 c. c, 10 c. c, and 20 c. c. of milk, the 
smallest quantity being added to a tube of freshly sterilized whole 
milk, while the other quantities were placed in empty, sterile test 
tubes. The milk, was heated to 80° C. for 10 minutes, then cooled and 
incubated under anaerobic conditions at 37° C. After 48 hours the 
tubes were examined for the typical stormy reaction. These quan- 
tities were found to be too wide apart to yield a satisfactory esti- 
mation of the number of spores, so the following method was advo- 
cated. Small, narrow tubes, about 4 inches by J inch, were used in 
batches of 10. The tubes were sterilized and 2 c. c. of milk added to 
each, making a total of 20 c. c. in the 10 tubes. The tubes were 
heated, incubated, and examined as mentioned above. Each tube 
which showed a typical stormy reaction was recorded as 1. Thus, 
if three tubes showed the reaction, the result was recorded as 3. 
Savage set the following arbitrary standard, which he says can not 
be considered a rigid standard : 
or 1 tube positive =good milk. 
2, 3, or 4 tubes positive =unsatisfactory milk. 
5 or more tubes positive— bad milk. 
A number of samples of milk produced under dirty conditions 
have been examined by the Savage 10-tube method. His method was 
