374 Biffen. — A Fat-Destroying Fungus, 
pressure through several thicknesses of filter-paper, a faintly 
brown opalescent fluid was obtained which gave a slight acid 
reaction. It showed no signs of oiliness. The extract was 
then neutralized with sodium carbonate and mixed with 2 
per cent, potassium cyanide solution, to inhibit the action 
of the Bacteria which had entered during the process of 
extraction, and then placed in quantities of about 5 c. c. in 
sterile plugged tubes for further experiments. 
In the first place thick sections of coco-nut endosperm were 
placed in three tubes containing the fresh extract, and in 
three containing the extract previously boiled and cooled 
to serve as a control. The tubes were kept at a temperature 
of 24° C. for a day, and the sections then taken out and 
stained over night in alkanet-extract. 
In the control experiment the sections showed no signs of 
change ; but in the sections from the tubes of fresh extract 
the oil had either completely disappeared or was reduced to 
a fine emulsion. 
A further series of tubes were then prepared as before ; 
but this time, instead of sections of endosperm, cover-slips 
coated with a thin layer of coco-nut oil were used. This 
substance is of special value in testing for lipases, as it is 
a pure fat free from acid, and contains, according to the 
analysis of Fresenius, 99-979 per cent, of fat 1 . The layer soon 
became liquid and formed an emulsion which floated on the 
surface of the extract and gradually diminished in quantity. 
Testing with litmus-paper showed that the liquid was acid, 
and on neutralizing with sodium carbonate solution the fatty 
acid formed floated to the surface 2 . The liquid had the 
same pleasant ethereal odour as the original nut. 
To another series of tubes of this extract a 2 per cent. 
1 Kew Bulletin, 1890, Art. clxxiii, p. 230. 
2 This acid was not investigated further. I may note here that the literature on 
the question of the constitution of coco-nut oil is confused owing to the unfortunate 
habit of spelling coco-nut ‘cocoa-nut.’ As pointed out by Balfour (Ann. Bot., 
vol. i, p. 1 84), this is a mistake. Thus in Watt’s Diet, of Chemistry, vol. ii, 
p. 231, we find ‘cocoa-nut-oil or cocoa-butter,’ cocoa-butter being the product 
of Theobroma Cacao ! 
