Dilution Separator 177 
is concerned, in diluting it with 25 per cent of warm 
water, this dilution cannot be regarded as a sub- 
stitute for setting without dilution in ice water, and 
it has the further disadvantage of requiring increased 
tank capacity. 
Aboat 1897 the idea that dilution with water is 
an important aid in gravity-creaming broke out with 
renewed activity. It was especially recommended by 
the manufacturers of certain forms of cheap tin cans 
in which dilution was recommended as an essential 
part of the process. These cans were called gravity 
“separators” modified by various high-sounding, 
qualifying phrases, with the evident intention of con- 
veying the idea that this process was as efficient as 
centrifugal separation, and large numbers of the 
“separators” have been sold, mainly to unsuspecting 
or ignorant farmers, who have been deluded into the 
idea that they were securing a contrivance equal in 
efficiency to a centrifugal separator at a small frac- 
tion of the cost. The form of many of the cans was 
patented, but it was soon shown* that so far as the 
process is concerned, the patents were valueless, and 
trials at several experiment stations showed that dilu- 
tion in gravity separators, of whatever form, is no 
more efficacious than has been shown above. For 
this reason, and because rival manufacturers have 
become involved in controversies over their various 
patents, the “dilution separator boom” is, fortunately, 
likely to be of short duration. ° 
Centrifugal separation.— The invention, develop- 
ment and perfection of the centrifugal separator has 
; ¥*Cornell University Agricultural Experiment Station, Bulls. 151 and 171. 
