SCIENCE AND INDUSTRY. 
the leather to the same atmospheric humidity. Eighty samples, includ- 
ing practically all the commercial materials used in waterproofing sole 
leather, were tested by this method. Only twenty were found to 
waterproof sole leather sufficiently to prevent its absorbing an average 
of more than 35 per cent. of water under the conditions of the test. 
This percentage was arbitrarily adopted as a limit for satisfactory 
materials for increasing the water resistance of sole leathers.” 
COST OF WORM NODULES. 
The losses incurred through the presence of worm nodules in Aus- 
tralian beef is illustrated by the following report by Mr. D. J. Kerr, 
Chief Veterinary Officer of the Department of Trade and Customs :— 
“When it is considered that 14 per cent. has had to be removed from 
each carcass of beef exported from Australia during the past ten years, 
and assuming the approximate annual average of cattle available for 
export from Australia as being 500,000 carcasses, that is of 5,000,000 
carcasses for the ten years of, say, an average weight of 650 lbs. each 
(total 3,250,000,000 Ibs.), the amount of 455,000,000 Ibs. (14 per cent.) 
has been excluded. Taking the average value of brisket meat during the 
past ten years at 2d. per lb. in Australia, and the exportable f.o.b. value 
as 4d. per lb., it will be seen that the loss to the industry has been 
enormous, 7.¢., £3,800,000 (approximately), or £380,000 per annum.” 
THE MANUFACTURE OF EPSOM SALTS IN AUSTRALIA. 
Until a few years ago, most of the Epsom salts used in Australia 
came originally from Germany. They occurred there as the compound 
kieserite, an important part of the great Stassfurt deposits of Germany, 
which was the source of supply also for the world’s potash. Germany, 
however, did not possess a monopoly of kieserite, and the salts were 
manufactured in America, India, Greece, and Italy. Now Australia is 
added to the list, and we have “ Made in Australia” Epsom salts instead 
of the “ Made in Germany.” Epsom salts is largely used as medicine, 
and may be regarded as a typical saline purgative. Its action is 
dependent upon the minimum of irritation of the bowel, and is exercised 
by the abstraction from the blood of water, which passes into the bowel, 
to act as a diluent of the salt. The stronger the. solution administered 
the greater is the quantity of water that passes into the bowel—a fact 
to be borne in mind when the salt is administered for the purpose of 
draining superfluous fluid from the system, as in dropsy. It also has 
a stimulating action on the glands. In Australia, magnesite is used as 
the source of supply. It is a fine-grained, compact mass, white to 
yellow, according to purity, hard and brittle, and is a carbonate of 
magnesia (Mg.CO;) This occurs in three different types of deposit :— 
(1) In irregular veins in magnesian igneous rocks. It is a 
decomposition product from the decay of the rock material. 
(2) In_beds associated with deposits of rocksalt, gypsum, &c. 
Here it is a direct deposit from concentrated saline waters. 
(3) In_beds interstratified with slate, shales, limestones, &c. 
Here it is due to replacement of lime by magnesia. 
In most of the workable deposits, it is from the first type that the 
material is obtained in Australia. 
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