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2. Powdered or desiccated milks. 
The object of reducing the solids of milk to a state of 
complete dryness is, of course, the same as that of the manu- 
facture of condensed milk, i.e., reducing the bulky! milk into a 
concentrated food product and thus reducing the cost of trans- 
portation to about one-eighth, and preserving the solids in a 
convenient and durable form. The first object is achieved in 
milk powders to a much higher degree and the second has in 
recent times been also realized in a remarkable measure. 
A great number of various patents have been registered 
in America and in European countries for the manufacture of 
milk powders. The first commercially known milk powder 
was that patented by Grimwade in England in 1855. All 
present methods are more or less variations and combinations 
of two main principles. 
One is that of applying milk, either fresh or partly con- 
densed, in a thin film or in a spray, to heated surfaces, usually 
steam-heated rollers. Perhaps the best known system based 
on this principle is that of Just-Hatmaker, in which the milk 
is sieved on two large horizontal, steam-heated, smooth-sur- 
faced revolving rollers. The heat of the rollers evaporates the 
water of the milk-drops almost immediately upon their strik- 
ing the surface. The solids drop off or are scraped off by 
knives in the form of fine scales or chips which are gathered 
below, and after being put through a grinding process the 
product is finished. Working more or less on this principle 
combined with vacuum chambers are the Eckenberg, the Bu- 
flovak, the Campbell and other processes. 
‘The second principle known as the “spray process’! has 
been introduced by the Merrell-Soule Company of Syracuse. 
/A current of hot air is produced by conducting pure filtered 
air through a system of steam-heated pipes. This hot air is 
circulated through open chambers by strong fans. Into this 
hot current the milk, which has been pasteurized and usually 
partly condensed, is injected by force pumps in:the form of a 
fine spray, producing a fog similar to that of spraying devices 
used for imparting fungicides or insecticides finely to the 
leaves of plants. The milk thus “atomised” is dried while in 
the air, and precipitates in the chamber in the form of a fine 
flour. No grinding is necessary, and the product may imme- 
diately be packed in tins. According to Stocking (Manual of 
