VENOMS IN THE ANIMAL SERIES 271 
alcohol at 50° C., and richer in azote (14 per cent.), to which 
he has given the name congestin. This is not destroyed by 
heating to 107° C. It is prepared by precipitating, by four times 
its volume of alcohol, a solution of anemone-tentacles in 5 per 
cent. fluoride of sodium. The solid matter, after being precipi- 
tated and dried, is redissolved in six times its volume of water, 
and then filtered. On adding to the filtered and fluorescent 
liquid its volume of alcohol at 90° C., the congestin is precipi- 
tated. It is purified by redissolving it in water, and freeing it 
by dialysis from the fluoride of sodium that it has retained. In 
this way there is obtained, after evaporation, a product sufficiently 
toxic to kill dogs in twenty-four hours in a dose of 2 milligrammes 
per kilogramme. 
Congestin exerts a sensitising or anaphylactic effect upon 
animals as regards thalassin, and is lethal in a dose of about 
5 milligrammes per kilogramme of animal, and sometimes even 
in a dose of 7 decimilligrammes. It is therefore a very active 
poison. 
Dogs, on the other hand, into which is injected first thalassin, 
and then, some time afterwards, congestin, are perfectly resistant 
to inoculation by the latter. Thalassin is therefore antitoxic ox 
antagonistic to congestin. 
The latter, on the contrary, if injected first of all in non-lethal 
doses, renders animals so sensitive to inoculation with thalassin, 
that from 4 to 5 milligrammes are sufficient to cause death. 
The tentacles of these anemones therefore contain two toxic 
substances antagonistic to each other, which can easily be separated, 
since one (thalassin) is soluble in concentrated alcohol, while the 
other is completely insoluble in this reagent. 
These poisons are not only extremely interesting from a physio- 
logical point of view, but also possess a practical interest, since it 
is at the present time almost a matter of certainty that they are 
the cause of a malady which specially affects sponge-divers in the 
Mediterranean. 
