SCIENCE AND INDUSTRY. 
—s 
In addition to the industries included above, certain others are 
engaged in the preliminary consideration of schemes for forming Re- 
search Associations. - 
DEHYDRATION OF MILK. 
A paper on the above subject was read at a recent meeting at 
Birmingham of the Society of Chemical Industry by Colonel J. G. 
Wright, of Toronto. Colonel Wright prophesied that before ten years 
haye elapsed we shall be purchasing our domestic milk supply by the 
pound at the grocery store instead of having it delivered in liquid 
form. The product now obtained by several processes is sufficiently 
good to allow the preparation of a fluid bearing a fairly close 
resemblance to fresh milk, or, at least, to heated or cooked milk. 
Discussing methods, Colonel Wright stated that in one process two 
hollow metal cylinders, arranged to revolve in opposite directions, are 
mounted so as almost to touch each other. The cylinder performs about 
fourteen revolutions per minute. The cylinders are heated internally 
by steam, so as to have a surface temperature of 100 ‘degrees ©.; the 
milk is first evaporated in vacuo to about one-quarter by volume; it is 
then pumped to the elevated containers over the cylinders. and is 
allowed to flow between; the concentrated milk spreads in a thin film 
over the surface when the cylinders haye completed one half-revolution, 
and the film of dried milk is scraped off and powdered in a powdering 
mill. In another process largely used in Canada, the milk is evaporated 
in vacuo; then the evaporated milk is forced through fine needle points 
under pressure into a chamber containing hot air, when the powder falls 
to the bottom, and does not require to be put through a powdering mill. 
Each of these processes requires a high degree of heat, and occupies 
about one hour to complete. The new process, which is to be used at 
St. Thomas’ Factory, Toronto, consists of two cells or chambers built 
of hollow tyle lined with tin. Each cell is 28 feet high by 21 feet square. 
At the top of the cell,.in the centre, is the spray; it consists of two 
circular dises about 16 inches in diameter, and placed 1} inches apart. 
Around the outer edge are placed a number of teeth. The sprayer was 
made to revolve by a 5 horse-power motor at 4,500 revolutions per 
minute. The milk is fed in by gravity, and sent out in a centrifugal 
spray, which is very finely divided. In the cell are sixteen openings, 
four on each side, to allow hot air to enter the cell. These openings 
are 4 feet long by 5 inches wide. The air is drawn from the outside 
through washers, and passed over furnaces driven by a 10-horse motor- 
power fan. On the walls of the floor level are placed exhausts. . The 
milk passes from the receiving station to the top of the first cell, and 
in passing through the latter 75 per cent. of the water is removed. It 
falls and flows out at the bottom into a container as concentrated milk. 
From this container it is pumped. up to a second cell, where the operation 
is completed; the balance of the water is extracted, and the milk flows 
‘to the bottom in powder, where it is caught by a fan and blown imme- 
diately into a cooling chamber on top of a sieve, through which it 
falls into a storage bin. Two cells have a capacity of 50,000 lbs. raw 
material each day, and were operated by three employees. The author 
pointed out that in the new process the milk never comes in contact 
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