Testing Milk and Its Products. 



INTRODUCTION. 



The need of a rapid, accurate and inexpensive method 

 of determining the amount of butter fat in milk and 

 other dairy products became more and more apparent, 

 in this country and abroad, with the progress of the 

 dairy industry, and especially with the growth of the 

 factory system of butter and cheese making during the 

 last few decades. So long as each farmer made his own 

 butter and sold it to private customers or at the village 

 grocery, it was not a matter of much importance to 

 others whether the milk produced by his cows was rich 

 or poor. But as creameries and cheese factories mul- 

 tiplied, and farmers in the dairy sections of our coim- 

 try became to a large extent patrons of one or the other 

 of these, a system of equitable payment for the milk 

 or cream delivered became a vital question. 



I. Nearly all the creameries in existence in this coun- 

 try up to about 1890 were conducted on the cream- 

 gathering plan: the different patrons creamed their 

 milk by the gravity process, and the cream was hauled 

 to the creamery, usually twice or three times a week, 

 where it was then ripened and churned. The patrons 

 were paid per inch of cream furnished. This quantity 

 was supposed to make a pound of butter, but cream 



