XVI. A STUDY OF TOAD POISON. 1 



By Dr. FR. PROSCHER. 



THE numerous investigations concerning toad poison which have 

 been made especially by French and Italian workers, have not yet 

 come to a definite conclusion as to whether this substance is alkaloid- 

 like or toxin-like. The skin secretions of the different varieties of 

 toads contain a number of bodies which have not thus far been studied. 

 In the garlic toad, for example, there is a substance of garlicky odor, 

 which has not been more closely identified. Besides this, according 

 to Calmels, toad secretion contains methylcarby laminic acid and 

 methylcarbylamin, which are said to act intensely on the nervous 

 system 1 . Robert applied the name "phrynin" to a substance whioh 

 irritates the mucous membranes very intensely. Phisalix and 

 Bertrand claim to have isolated an alkaloid from the blood serum 

 of the common toad, but it remains doubtful whether the substance 

 was not a toxin, for they were unable to produce it in chemically 

 pure form. At the conclusion of their investigations they themselves 

 say that the poisonous action is not due entirely to the " alka- 

 loid." In like manner Jornara and Casali claim to have isolated 

 "bufidin" from dried toad poison. They say that this forms crystal- 

 line salts and must therefore be an alkaloid. The alcoholic extract 

 of toad skin is said to have an action similar to digitalis. Pugliese 

 found that toad poison changes haemoglobin into methsemoglobin, 

 and that it also dissolves the blood-cells outside the body. Pugliese 

 has not attempted any more detailed investigation. From the 

 abstracts of his study at my disposal I was unable to determine the 

 species of toad used in his experiments. 



The object of the following investigation is to furnish a small 

 contribution to our knowledge of toad poison. At present there 

 can be no thought of any exact analysis of the poison. 



1 Reprint from Beitrage zur chemischen Physiologie u. Pathologie, Vol. 1, 

 Nos. 10-12. 



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