DAIRY FARMING DAIRYING. 793 



"Perhaps the most interesting result has to do with the production of the hatter 

 aroma. The hutter aroma, the character that a fleets the nose rather than the pal- 

 ate, appears to he, at least so far as the results of the experiments are concerned, 

 entirely independent of the flavor. Moreover, it appears to be a more unusual 

 thing for bacteria t<> produce a desirable aroma than a desirable flavor. The greaJ 

 majority of these species tested give rise to practically none, or at least to an 

 extremely slight aroma. Thirty-uine produce no aroma at all, [and] the majority, 

 again, are among the class which either develop an alkaline reaction in the cream or 

 do not change its reaction at all. Seven of those producing no aroma are among the 

 class that produce lactic acid. Among those that do produce an aroma of a decided 

 character, 18 are described in my laboratory notes as producing an unpleasant or a 

 bad aroma; 7 of these are among those that produce lactic acid. . . . Only 8 have 

 been found as yet to produce an aroma which has been described in my notes as 

 good ; and in only 3 has the aroma been that which is looked for in first-class butter. 

 In 2 or 3 eases the aroma produced was of an extremely fine character, and in 

 the>e artificial tests almost identical with the aroma expected in the first-class butter 

 from a creamery. It has been interesting to find that, of the 8 species which pro- 

 duce the aroma which has been described as good, none has been among the acid- 

 producing organisms. The 8 either develop an alkaline reaction or have no special 

 effect upon the reaction of milk. There were 3 which developed the most typical 

 aroma of all the species studied. Two of these curdled milk by producing a ren- 

 net, both liquefying gelatin. The third did not curdle the milk. This result has 

 been a surprise to me, inasmuch as I hail supposed before the experiments began that 

 the aroma was a matter very closely associated with the development of the lactic 

 acid. . . . 



"It has been found in these experiments thus far that none of the species tested 

 combines all of the 3 characters — the power of producing flavor, acid, and aroma. 

 Some develop flavor with the acid, others develop aroma with flavor, and others 

 develop aroma without any special flavor. As yet no single species has been dis- 

 covered that produces all simultaneously. This result is not, of course, surprising, 

 for, recognizing that the ripening of cream must bo an extremely complicated process, 

 and produced by a large number of species of bacteria working together, it is a nat- 

 ural inference that the different qualities in the butter may be caused by different 

 species of bacteria. It is by no means to be implied, however, that the 3 properties 

 may not be combined in some species of bacteria." 



In conclusion, it is noted that some of the species of bacteria pro- 

 ducing good flavor in the butter were quite widely distributed during 

 the month of June. One species in particular which gave a good flavor 

 and a strong acid was found during the months of May and June in 

 each of the creameries from which cream was taken. This is suggested 

 as a possible explanation of the generally high quality of butter made 

 during these months. 



Bacillus acidi lactici and other acid organisms found in Amer- 

 ican dairies, W. E. Esten {Connecticut Starrs Sta. Rpt. 1890, pp. 44- 

 52). — This is the result of a study of the occurrence of these organisms 

 in milk from different sections of the country. Samples of milk were 

 collected within a wide extent of territory, including the Xew England 

 States, New York, Pennsylvania, and Ohio. Fifty-three samples of 

 milk were obtained from 30 different dairies. From these, 111 colonies 

 were isolated, 34 of which were discarded as not producing acid or as 

 being nearly anterobic; and of the 77 remaining 47 appeared to be 

 the same species — Bacillus acidi lactici. 



