THE TOXIC ACTION OF SAPONIN. 
By Raymonp Foss Bacon and Harry T. MARSHALL. 
(From the Biological and Chemical Laboratories, Bureau of Science.) 
In connection with the previous article, a few experiments were made 
in order to determine whether the saponin described therein has toxic 
properties similar to those of other saponins. 
Most of the studies upon this subject have appeared from Kobert’s 
laboratory at Dorpat (4; 5; 7; 11). The saponin substances examined 
there were found to be general protoplasmic poisons—that is, substances 
which injure or kill all forms of protoplasm with which they come in 
contact, without producing any alteration recognizable by present chemical 
methods. When rubbed on the skin saponin exerted no action and was 
not absorbed. It was strongly irritating when applied to the con- 
junctival mucous membrane. When injected subcutaneously into frogs 
it was quickly absorbed and acted upon nerves and muscles. In warm- 
blooded animals there was little or no absorption, the Saponin causing 
an aseptic abscess in the subcutaneous tissue. Intravenous injection of 
even small amounts proved fatal for cats and dogs, the animals dying 
without hematuria and without diarrhoea. 
Saponin exerts an immediately deleterious action on striated muscle 
and heart muscle, the change being evident upon microscopic examina- 
tion. Sensory and motor nerve fibers, nerve endings, and the central 
nervous system are all affected seriously. Saponin also acts upon the 
digestive tract, causing inflammation, and increasing peristalsis. Kobert 
suggests that this action is due to thrombosis of the intestinal vessels, 
starting from the detritus of hamolysed corpuscles. A 5 per cent 
solution proved to be rapidly fatal for a worm devoid of a chitinous 
covering (Taenia cucumerina), while the protected Ascaris was not 
affected after twenty hours spent in such a solution. 
The saponin substances dissolve the blood corpuscles of probably all 
mammals, and they penetrate the corpuscles very rapidly. It seems 
likely that the hemolytic action of these substances depends upon 
hydration and liquefaction of the (hypothetical) cell membrane. 
As was pointed out by Ehrlich (3), the hemolytic action of the 
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