= 
21 
‘Milk Products), the inventor of the process of desiccation by 
spraying into a current of hot air was Robert Stauf, a German, 
who patented it in 1901. The patent was bought by the Mer- 
‘rell-Soule Company in 1905, and applied to milk. On this 
principle the Merrell-Gere process patented in 1907 is based. 
The process is no doubt a great improvement over former 
methods. By this almost instantaneous evaporation of the 
water while in the air and without the subjection of the milk 
ry 
caresy 
te high temperatures, the precipitating solid constituents are 
left in their natural state. They readily dissolve again in 
water, and the qualities of fresh milk are practically unim- 
paired. ; 
Whole milk, cream, skim-milk, buttermilk and whey can be 
ald are thus desiccated to powder. At present it is chiefly pow- 
dered skim-milk which gets into the open market. Powdered 
whole milk and cream, though perfectly sound in a fresh state, 
lack in keeping quality on account of the butter fat they con- 
tain, which is subject to becoming rancid, a decomposition in 
which buttiric acid is formed, giving rise to the familiar odour 
and taste of rancid butter. Powdered skim-milk is of much 
‘superior keeping qualities. For the industry as a whole this 
is hardly a serious disadvantage. Fresh cream and butter are 
_always in demand. The combination, of the cream and kutter 
business with the manufacture of skim-milk and buttermilk 
powders offers the way to an almost ideal conservation of all 
food value in the milk. Popular prejudice against skim-milk 
and the ignorance which rates the food value or “richness” of 
milk solely by the content of butter fat or “cream” is the only 
‘obstacle to a wide extension of this industry. 
As to these milk products in general (condensed, evapo- 
rated or dried milk), it may be said that they can be classed 
among the purest food products on the market. Good milk is 
used to start with, and it is immediately worked up. It is pas- 
teurized, and in the case of evaporated milk sterilized. No 
foreign matter is added, except pure sugar in the case of con- 
densed milk and some milk powders. As a rule no preserva- 
tives, flavoring or coloring matters are added. The addition 
of small quantities of bicarbonate of soda or lime, cream of 
tartar, or similar basic substances has occasionally been tried, 
‘in order to neutralize excessive acidity of milk. But it has 
‘been fuund out that it is much better to use only the best qual- 
