199 
in the fruit of Cucumis utilissimus , Roxb. 
neutralisation involved the decomposition of the cyanide, it 
was thought advisable to add another preservative agent. 
Attention has recently been directed by several observers 
to oil of mustard 1 as possessing strong power in this direction, 
and it was therefore chosen. About 30 cc. of each extract was 
put into a bottle furnished with a graduated scale, and a 
measured quantity of egg-albumin, prepared as before, was 
added. Each was then shaken up with 1 cc. of oil of mustard, 
and placed in the incubator. The oil of mustard is very 
slightly soluble, and a good deal of it floated on the top of 
the liquid. Being somewhat volatile, the air in the upper 
part of the bottles contained some of its vapour. As the 
action of the extracts proceeded the antiseptic was found to 
work admirably, no putrefactive changes taking place all the 
time it was continued— -a period of several days. 
The mode of observation was to shake the graduated 
bottles every morning, and on the albumin settling to the 
bottom, as it did in about 2-3 minutes, to measure the quan- 
tity remaining by the scale. 
The following table will enable a comparison of the activity 
in the two cases to be made : — 
Time of digestion. 
Diminution of albumin 
in C. 
Diminution of albumin 
in D. 
36 hours 
16% 
8% 
60 „ 
25 % 
1 8 Vo 
108 „ 
29% 
O 
X 
0 
0 
Cl 
The extract C had 
thus evidently greater ferment-power 
than D, and it is fair therefore to infer that the enzyme is 
more easily extracted by a weak salt solution — a fact which 
points either to its being a globulin in nature, or more 
probably associated with a globulin constituent in the cells 
of the plant. The fact that the first watery extract made 
possessed ferment-power would be explained by the fact that 
in the plant are many inorganic salts, by whose assistance it 
would be dissolved on the addition of water. 
1 Among others, Cadeac et Mennier, Recherches experimen tales sur Taction 
antiseptique des essences, Annales de l’institut Pasteur, iii. 1889 ; also Roux. 
