1028 
is sufficient to kill a rabbit in a few minutes. The action of this saponin 
on fish is apparently the same as that of the one from Hntada scandens. 
These saponins are particularly advantageous for use as fish poisons, 
because, whereas many are very poisonous when injected, they are usually 
only slightly so when taken into the stomach; so that even if the fish is 
somewhat contaminated with these substances no harm will come from 
eating it. 
Two fish poisons of a different class have also been examined. One is 
Derris polyantha Perk. (Leguminosew), containing a poisonous alkaloid, 
and the other is Diospyros canomoi D. C.*" (Hbenacee), a plant which 
is endemic, common, and widely distributed in the Philippines, the part 
used being the fruit of the tree, which turns black after a few days’ expo- 
sure to the air. The natives claim that the fruit is exceedingly poisonous, 
that it will quickly kill fish, and will even cause a crocodile to leave the 
water. They also maintain that the juice of the berry, when applied to 
the human skin, blisters it and causes it to turn black. The following 
preliminary study of the fruits of this plant has been made: 
(a) Two lots of 50 grams each of the ground, fresh berries were soaked for 
twenty-four hours in 100 cubie centimeters of water (No. 1) and 100 ecubie centi- 
meters 1 per cent sulphuric acid (No, 2), respectively, and alkali, equivalent 
to the sulphuric acid, was then added to the second portion. The extract was 
now separated from the berry pulp in a hydraulic press. Both solutions were 
intensely black. No alkaloid or glucoside could be found in either. 
The physiological tests were as follows: 
Eaperiment A.—Guinea pig of 210 grams: 1 cubic centimeter of solution No. 1 
given intraperitoneally. The animal is weak in a few minutes, and it is sick 
during this day and dead on the next morning. An autopsy reveals much irrita- 
tion and congestion of the abdominal organs, with large amounts of bloody 
exudate, but no pus. 
Baperiment B.—Guinea pig of 230 grams: 1 cubic centimeter of solution No. 2 
given intraperitoneally. There is marked irritation from the time of the injec- 
tion with symptoms as in Experiment A, but after forty-eight hours of weakness 
there is complete recovery. 
Eaperiment C.—Guinea pig of 200 grams: 1 cubic centimeter of No. 1 given 
subeutaneously. The substance is evidently quite irritating, the animal making 
efforts to bite the place of injection, it is quiet for some hours, but with no other 
marked effects, and complete recovery ensues, 
Eaperiment D.—Guinea pig of 205 grams: The results duplicate Experiment C 
in every respect. 
Eaperiments E and F’.—On these guinea pigs an area of about 6 square centi- 
meters is shaved and 0.5 cubic centimeter of extract No. 1 rubbed into the skin. 
It evidently affects the sensory nerves quite markedly. For several days after- 
wards the skin at the place of application showed a marked rash and appeared 
darkened, rough, and leathery. 
(b) Three hundred grams of the fresh fruits were now subjected to a pressure 
of 400 kilos per square centimeter in a hydraulic press, 90 grams of a black liquid 
* Prodr. (1844) 8, 237; D. multiflora Blanco. Fl. Filip. (18387), 3803; Hiern. 
Monog. Eben, (1873), 216, non Wall. 
a 
