220 Report of the Chemical Department oe the 



INTRODUCTION. 



The investigation described in this bulletin had its origin with 

 the U. S. Department of Agriculture, and was under the charge 

 of Henry E. Alvord, Chief of the Dairy Division of the Bureau 

 of Animal Industry. This Station was asked to cooperate in the 

 v.ork, which it did by securing parties to furnish the cheese used 

 in the investigation, by suggesting conditions of experiment, by 

 assisting in the commercial examination of the cheese from time 

 to time, by making analyses of the cheeses at intervals and by 

 keeping the records of the work. B. F. Van Valkenburgh, ot 

 New York City, gave immediate personal supervision to the work 

 on the part of the U. S. Department of Agriculture. 



The plan of the experiment was to secure cheeses representing 

 the states of New York, Pennsylvania and Ohio, to place these 

 in cold storage at different temperatures, to have commercial 

 examinations made from time to time by a committee of chosen 

 experts, to weigh the cheeses at intervals and to make chemical 

 analyses of them. The object of this work was to stvidy during 

 the curing process the effect of dififerent temperatures and the 

 effect of covering cheese with paraffin, upon (i) the commercial 

 quality of the cheese, (2) the loss of weight, and (3) the chemical 

 changes taking place. 



DETAILS OF INVESTIGATION. 

 description of sources and character of different lots 



OF CHEESE used IN THE EXPERIMENT. 



The arrangements for carrying on the experiment were not 

 completed until the latter part of September, when it was some- 

 what difficult to secure large-sized cheeses, because most of the 

 factories were making only the small home-trade size. We were 

 able, however, to get the makers in two cases to make the large- 

 sized cheeses for this special work, but they were not of the best 

 quality in every respect. 



Lot I (B p/OJ comprised 21 cheeses, averaging 64 lbs. each 

 in weight, made by A. B. Hargrave, at Heuvelton, St. Lawrence 

 county, N. Y. These were made from the mixed milk of Sep- 

 tember 26, which contained 3.8 per ct. of fat. The milk was 



