FAT. 107 
way, one may readily succeed in rendering visible, for instance, 
the fatty oil of Lycopodium, of which the latter contains near ly 
50 per cent, but which does not admit of recognition by simple 
microscopical observation ; it is only necessary to crush the 
grains, and then to add the sulphuric acid or concentrated solu- 
tion of calcium chloride. 
In seeds, the fats play the part of reserve substances, and in 
living tissues, particularly those containing chlorophyll, they 
are an assimilation product, which evidently finds at once fur- 
ther application in building up the tissues. 
The fats are soluble in boiling alcohol, in ether, carbon bisul- 
phide, benzol, paraffin and volatile oils, and are colored brown- 
ish-black by osmic acid. 
With those seeds which contain fatty oil most abundantly, 
this may exceed half the weight of the kernels (after the removal 
of the seed-shells). Thus in Amygdalus, Cacao, Papaver, 
Ricinus, Sesamum, and Croton Tiglium ; in the latter, the oil 
amounts to nearly 60 per cent. For the most part, however, 
the amount of fat of other seeds which concern us here is 
small; linseed and black mustard afford about 33 per cent of 
oil. 
‘The fat of the olive, the yellow palm-oil, as also the so-called 
Japan-waz, are contained in the fleshy portion (sarcocarp) of | 
the fruits of the respective plants from which they are derived. 
‘The remaining solid and liquid fats of the vegetable kingdom, 
which are brought in large amounts into the markets of the 
world, are furnished by seeds. 
The fats are esters (compound ethers) of propenyl or glycerin. 
The acids combined with this radical belong mostly to the 
series of the ordinary fatty acids, although a portion of very 
many fatty oils and even of. solid fats consists of olein, 7. e., of 
the propenyl ester of oleic-or elaic acid, which belongs to the 
acrylic acid series. Nowhere has a propenyl ester been proved 
to exist singly in nature ; every fat is a mixture of several such 
esters. When a fat is dacounposed (saponified) by means of a 
caustic alkali, the base is therefore —— found to becombined — 2 
with more than one acid. 7 as so ag 
