VARIOUS METHODS OF SETTING MILK. 65 



" Third, There was a noticeable uniformity between the sizes of the 

 globules of each sample, the first cream taken from tlio machine having 

 larger globules than the last cream. When, however, the machine was 

 rmi continuously, this should become not so evident. 



"The specific gravity of the centrifugal cream as taken from jars pre- 

 pared for market was 9G2 ; and a later result, made a few weeks ago, gave 

 95G.50. It is evident that this specific gravity could be greatly reduced 

 by allowing the ci'eam to remain under centrifugal force influences a 

 little longer before removal. 



"After a large quantity of milk has been passed through the machine, 

 a quantity of dirty, greenish, olfensive slime, is found to accumulate, as 

 I am told by Mr. Burnett, upon the circumference. Some of this was 

 brouglit me for examination. It appears to consist, as the microscope 

 afterwards verified, of the impurities which existed in the milk." 



The butter obtained from the centrifugal cream is like any 

 other good butter, except that we have noticed a slight loss 

 of color. 



An important fact lately developed by Dr. Sturtevant is 

 its melting-point, 98°, being remarkably high. He found 

 exactly the same result, however, from my own dairy as from 

 that of my neighbors, which furnished two samples from the 

 same milk treated by the machine and by the ordinary pro- 

 cess, and was 98° and 94° respectively. 



At present I am using two machines, — one continuous, 

 and the other intermittent ; and, like my first macliiue, these 

 were invented and built by D. M. Weston of Boston. They 

 are constructed in almost every particular like a centrifugal 

 hydro-extractor. 



The most favorable results are obtained when the milk is 

 warm from the cow: it then throws off the thickest cream in 

 the sliortest S2")ace of time. 



Let me here state that the pressure exerted on the Avails cf 

 the c^'lindrical basket of a two-foot machine at two thousand 

 revolutions per minute is two hundred pounds to the square 

 inch, or fifty pounds greater than a government inspector 

 requires on a new high-pressure steam-boiler : so that a ma- 

 chine must not only be constructed of the best material, but 

 in the most thorough and workmanlike manner. 



In an excellent paper by Dr. T. E. Engleliardt of Syra- 

 cuse, N.Y., on the result of European experiments, he says, 

 for each experiment contained in the following table two 

 hundred pounds of milk were used; and the correctness of 



