

BACTERIA IN THE DAIRY. 67 
dairy in which he made butter of a very high grade. In the 
month of September he obtained the first premium in a county 
fair which was held in Fitchburg, Mass. Knowing of these 
experiments, however, he wished to try the effect of Baczllus 
Vo. gi upon his butter, and a culture was furnished him and 
used in the usual manner. -The report which he subsequently 
sent me was that his butter was decidedly improved by the use of 
the artificial culture. He continued the use of the culture for 
several weeks, believing that he obtained a better butter thereby. 
In a letter written subsequently he informed me that his butter, 
during the period of the use of the culture, had been better than 
was common at that season of the year, though whether to— 
attribute it to the culture or to the food eaten by the cows, he did 
not know. 
So uniform have been the results of the use of this organism 
that it must be regarded now as beyond the reach of experimen-— 
tation, and Bacillus No. gr takes its rank as a species of organ- 
ism whose artificial use in the ripening of cream will produce a 
striking improvement in the flavor of the butter. The effect of 
the culture upon the various grades of butter is not exactly what 
might have been expected, and I have been considerably sur- 
prised thereby. When the experiments were begun I had sup- 
posed it probable that the use of the artificial culture might 
improve a poor quality of butter, but was very doubtful whether 
it would have any effect, at least any advantageous effect, upon 
first-class butter. Experiments, however, have shown that the 
organism appears to be of decided value even in first-class cream- 
eries. As already mentioned, the effect of the organism appears 
to be to add to the butter an especially delicate aroma and taste, 
and this delicate aroma and taste is added equally to butter of a 
poor grade and medium grade, or to butter of the very highest 
quality. In the light of the present experiments, therefore, it 
appears that all grades of butter may be somewhat improved by 
the use of artificial cultures. 
- Another matter of some interest is the fact that Bacillus No. 
gi is not a milk-souring organism. The “ripening ”’ of cream is 
in many places called the ‘“‘souring” of cream, and it has been 
supposed by all experimenters hitherto that the souring was 
identical with the ripening. For this reason all of the species of 
bacteria which have hitherto been used in ripening cream have 
been acid producing organisms. Experimenters have not thought 
