HOW SCIEXCE IS HELPING THE FARMER. 105 



class of the two, the butter dairyman can only afford to keep prof- 

 itable cows, and the thousands of creameries over the country 

 can not afford to purchase good and poor milk for one and the 

 same price, for that is unjust to the person supplying the best 

 grade of milk. Consequently, for some years chemists have been 

 laboring to invent some simple method of determining the per- 

 centage of fat in milk, bo that creamery men and farmers with a 

 common education might be able to use it, and thus test their 

 milk accurately. The first method for practical application among 

 farmers to attract very general attention was that devised by Mr. 

 F. G. Short, chemist to the Wisconsin Experiment Station, whose 

 method was published in 1888.* This, however, was somewhat 

 complex, and too slow of operation. Other methods were after- 

 ward developed by Messrs. Patrick, Parsons, Cochran, Babcock, 

 etc. Dr. S. M. Babcock, while chemist at the Xew York State Ex- 

 periment Station, did much valuable work in the study of milk 

 and its products, and in 1889, after becoming chemist of the State 

 Experiment Station at Madison, Wis., he developed and brought 

 out a method for testing the fat in milk or cream that is now a 

 recognized success. The method is simple, and can easily be per- 

 formed by any person of fair intelligence. Equal quantities of 

 milk and sulphuric acid are placed in specially constructed bot- 

 tles, and these put in a simple machine, largely consisting of a tin 

 cylinder or wheel, about fifteen or twenty inches in diameter, re- 

 volving on its side, within which, after the manner of spokes, are 

 cups or pockets, in which these bottles are placed. The wheel is 

 revolved by a crank and cog movement, and by centrifugal force 

 and the action of the acid the fat in the milk is separated from 

 the rest of the fluid. Enough hot water is added to each bottle 

 to fill the measuring neck, and the fat, after five or six minutes' 

 turning of the machine, comes to the top clear and yellow, after 

 which the amount present may be read upon the graduated lines 

 on the sides of the long neck of the bottle. The milk of as many 

 as twenty-four cows can be tested in an hour. Machines of from 

 four to fifty bottles capacity are manufactured. 



This invention, the result of long and laborious scientific re- 

 search, is not patented, and is largely used in the creameries of 

 Wisconsin, Iowa, Illinois, and many other States in the purchas- 

 ing of milk. The patrons of the creameries are paid for their 

 milk according to its quality, as decided by the Babcock machine. 

 Such a method as this is a blessing to the country, for it informs 

 the farmer if his milk is inferior to that of his neighbor, and will 

 consequently incite him to improve his stock. 



* University of Wisconsin Agricultural Experiment Station, Bulletin No. 16, July, 1888. 

 A Xew Hethod for determining Fat in Milk. 



