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obtained for the by-product, “coconut cream.” Vacuum drying is not of 
great value in the desiccation of coconuts for oil-making purposes. 
(10) Although a pure coconut oil is not a suitable medium for a growth 
of micro-organisms, one containing a sufficient amount of nutrient matter 
and moisture may, under certain conditions, develop a growth of mold 
which rapidly attacks the oil itself. A sample of pure oil to which had 
been added 1 per cent of “latic’” and 1 per cent of water increased in 
acidity from 0.10 per cent to 8.63 per cent on standing exposed to mold 
action in an incubator for one week. 
The very slight increase in acidity which a pure oil suffers on long 
standing is probably due to simple hydrolysis by heat and moisture. 
(11) Besides the production of free acid by molds and the decomposi- 
tion of albumen by bacteria in moist copra and in impure oils, one other 
factor enters into the deterioration of coconut oil. Many samples on 
long standing develop a slight but noticeably acrid taste and odor, with- 
out any marked increase in acidity. Such oils invariably give a blue 
coloration with Schiff’s aldehyde reagent, reduce silver nitrate in Becchi’s 
test for cotton-seed oil, and possess the power of liberating iodine 
from potassium iodide.** 'This process is shown to be a direct oxidation 
by the air and to depend largely upon the amount of surface exposed. 
Other conditions favoring it are freedom from moisture and impurities, 
as is shown by the fact that impure commercial oils, or those which 
have been acted upon by mold, do not, as a rule, respond to tests for 
peroxide and aldehyde, while the most marked development of these bodies 
is noticed in the purest oils. 
(12) The action of light and air on coconut oil is of relatively little 
importance in comparison with the great changes produced by mold 
growth, and it can be prevented in a large degree by keeping oil receptacles 
as nearly full as possible, so as to reduce the amount of surface exposed. 
* Since writing the above I find that L. Legler [Pharm. Centr.-H. (1904), 45, 
839] has noticed the same phenomenon in oxidized lard. As a test for active 
oxygen he proposes to shake the sample with a solution of neutral lead acetate 
and a few drops of ammonia. <A yellow coloration, due to the formation of 
hydrated lead peroxide, indicates the presence of oxygen. I have applied this test 
to old coconut oils and find that, with highly oxidized samples, it gives a strong 
coloration, but it is not as delicate as the simple reaction with potassium iodide. 
To the presence of active oxygen Legler attributes the reduction of silver nitrate 
in Beechi’s test given by samples of oxidized lard entirely free from cotton-seed 
oil. I have observed the same fact when applying Becchi’s test to pure, but 
oxidized, samples of coconut oil, but considered it more logical to attribute the 
reduction to aldehyde-like bodies present in the oil, rather than to the active 
oxygen. 
