COMPOSITION OIF LINSEED OIL. 145 
Arabine by chemists; the other portion is merely suspended, 
and is considered to be analogous to the Bassorine, found chiefly 
in Gum Bussora, and in Cherry-tree Gum. Alcohol produces a 
white flaky, and acetate of lead, a dense precipitate in 
mucilage of Linseed. 
Linseed oil, which we have seen is contained in the kernel 
of the seeds, is obtained by expression, and may be either cold- 
drawn, or, as usually obtained, after the seeds have been sub- 
jected to a heat of 200°. The former, as in the case of cold- 
drawn castor oil, is paler, with less colour and taste than 
Linseed .oil prepared with the aid of heat. This is of a deep 
yellow or brownish colour, of a disagreeable smell and taste, 
specific gravity 0-932, soluble in alcohol and ether; differing 
from many other fatty oils, especially in its property of drying 
into a hard, transparent varnish—a peculiarity which is 
increased by boiling the oil, either alone, or with some of the 
preparations of lead. 
“The yield of oil from a bushel of East Indian seed is 142 1b. 
to 16 lb.; of Egyptian, 15 lb; of Sicilian, 14} lb. to 153 lb.; 
of Russian, 11 lb. to 13 lb.; of English or Irish, 102 lb. to 12 
Ib.”’ 
Linseed oil, according to Sace, is composed of Margarine 
and Oleine in nearly equal proportions. But the oleic acid of 
Linseed differs from that of other fatty bodies. The anhydrous 
acid is composed of carbon 46, hydrogen 38, oxygen 5. The 
Margaric acid is as usual composed of carbon 34, hydrogen 33, 
oxygen 8. The Glycerine obtainable from Linseed oil in large 
quantities, is also similar to that procured from other fats. 
Linseed, after having had the oil expressed from them, are 
in the form of a flat mass, commonly called oil-cake. This 
being reduced to coarse powder, forms the Linseed meal which 
is so commonly employed for making poultices, though these 
are also formed of the simply powdered seeds. Here it is 
evident, from the internal oleaginous and external mucilaginous 
parts being all ground together, and their properties elicited by 
hot water, an admirable mixture is produced for making a 
readily made emollient poultice. From the chemical compo- 
sition, it is also evident how nourishing the Linseed is likely 
to be, and, indeed, from experience, is well known to be, for 
fattening cattle. 
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