494 poisons : their effects and detection. [§ 647. 
fine needles or in thicker prisms ; after repeated crystallisation the m.p. is 
152°. Bufonin is soluble in chloroform, benzene, and hot alcohol ; not 
very soluble in ether, nor in water, nor in cold alcohol. A little 
bufonin dissolved in chloroform, and then strong sulphuric acid added, 
so as to form two strata of the liquids, gives at the point of contact a 
deep red zone. On mixing the chloroform solution this becomes dark 
red and, finally, purple red. The acid shows a green fluorescence 
Bufonin dissolved in acetic anhydride and mixed with strong sulphuric 
acid gives the same play of colours as cholesterin—the final colour is 
dark green. Phisalix and 0. Bertrand, 1 however, consider bufonin as 
simply cholesterin mixed with a little bufotalin. 
Bufotalin is obtained from the same alcoholic extract. After sepa¬ 
rating the bufonin, by treating the residue with water, adding lead 
acetate to purify, getting rid of the excess of lead by the addition of 
just sufficient sulphuric acid, and precipitating the bufotalin by mer¬ 
curic potassium iodide, the precipitate is treated with silver oxide and 
shaken with chloroform ; from the chloroform solution the bufotalin 
may be obtained by precipitating with petroleum ether. 
Bufotalin is easily soluble in alcohol, chloroform, acetic acid, and 
acetone ; it is not very soluble in water, about 2J per million ; it is 
insoluble in petroleum ether. The reaction in water is acid, and it 
forms soluble compounds with the alkalies. It is precipitated by tannin, 
but from such precipitate cannot be recovered, forming apparently 
fast compounds with zinc or lead oxide, the reagents used to decompose 
tannates. 
Bufonin and bufotalin possess similar poisonous properties ; but the 
action of bufonin is much weaker than that of bufotalin. 
These substances are heart poisons, and have a similar, if not an 
identical, action to the digitalins ; in this connection it is interesting to 
observe that the digitalis group has but little action on the toad, and 
that the blood of the toad contains probably the same poisons, i.e. 
bufonin and bufotalin. The lethal dose of bufotalin, according to 
Faust, for mammals is J mgrm. per kilo, of body weight (1 per two 
million) if injected subcutaneously ; but very much larger doses may 
be taken by the mouth. When swallowed, bufotalin excites considerable 
irritation of the mucous membrane of the alimentary tract, causing 
sickness and diarrhoea ; if applied to the conjunctiva, the eye becomes 
red and inflamed. 
§ 647. The Heloderma. —The Mexican lizard Heloderma Inorridum , as 
well as H. suspectum, have furrowed teeth and an enormously developed 
submaxillary gland, so that on anatomical grounds one would surmise 
that their bite was poisonous. Experiments have shown that the secre¬ 
tion is highly toxic, killing small animals, such as rabbits, in a very few 
1 Compt. Rend., 1902. 
