1894 THE MICROSCOPE. 101 



the miscellaneous collection of bacteria which chance to 

 be furnished him from the various sources from which 

 the cream is obtained. Now if it chances that the prop- 

 er species of bacteria are present in sufficient quantity, 

 the resulting butter will be of a proper quality, but if, 

 as is frequently the case, improper species of bacteria 

 are present in greater number and the proper species in 

 only small quantity, the resulting butter will be of a poor 

 quality in spite of every attempt made on the part of the 

 buttermaker to improve it. 



As our butter is each year being made more and 

 more largely in central stations or creameries, this im- 

 possibility of controlling the ripening process becomes a 

 more and more serious matter, and creameries producing 

 several hundred pounds of butter per day are largely 

 handicapped by the presence of improper species of 

 bacteria in the cream. In spite of every precaution 

 taken on the part of the buttermaker or the creamery 

 superintendent, such species cannot be avoided and give 

 a poor quality to the whole creamery product. Difficul- 

 ties from this source do occur occasionally in the very 

 best creameries, and very commonly occur in creameries 

 that do not pay the strictest attention to the condition 

 of the patronizing dairies. If butter making is to be 

 still further concentrated and produced in creameries in 

 still greater proportion, the desirability of controlling 

 the ripening process becomes greater and greater. 



Now as the result of bacteriological experiments a sol- 

 ution of this problem appears to be close at hand. It is 

 theoretically only necessary to find and cultivate the 

 proper species of bacteria and to furnish such cultures 

 to the creameries for artificially inoculating their cream 

 in order to produce a uniform good product. Of course 

 many difficulities arise in the way of the practical appli- 

 cation of such methods. The work upon bacteria is 

 nauch more difficult than the work upon yeasts, and it 



