Bufotalin is readily soluble in alcohol, chloroform, acetone, acetate of ethyl, and acetic acid. When water is added to a solution of it in alcohol it is precipitated, giving a white emulsion, which has a very bitter taste. From the aqueous extract whence the bufotalin has been separated, it is possible to separate a second poison, which acts on the nervous system and causes paralysis. In order to obtain it in a pure state, the extract is treated with alcohol at 96° C., filtered and distilled; the residue dissolved in water is defæcated with subacetate of lead and sulphuretted hydrogen. The solution thus obtained is successively exhausted with chloroform to extract the cardiac poison, and with ether, which removes almost the whole of the acetic acid. The second neurotoxic principle, called _bufotenin_, remains in the residue of the solution after being evaporated _in vacuo_. Toad-venom, therefore, contains two principal toxic substances: _bufotalin_, which is of a resinoid nature, soluble in alcohol, but scarcely soluble in water, and is the _cardiac poison_; and _bufotenin_, which is readily soluble in those two solvents, and is the _neurotoxic poison_.[161] Pröscher, on the other hand, has extracted from the skins of toads a hæmolytic substance, termed by him _phrynolysin_, which possesses all the properties of a true toxin and is not dialysable. It is obtained by pounding the skins with glass powder in physiological serum. Phrynolysin dissolves the red corpuscles of the sheep very rapidly, and (in order of sensitiveness) those of the goat, rabbit, dog, ox, fowl, and guinea-pig. The red corpuscles of the pigeon, frog, and toad are scarcely affected. When heated at 56° C. it loses its properties. By the ordinary methods of immunisation it is possible to obtain a very active antilysin. There is, therefore, a very close analogy between the venoms of _toads_ and _salamanders_. These highly complex substances are composed of mixtures of poisons, some of which are in all respects analogous to the vegetable alkaloids, while others are closely related to the microbic toxins and snake-venoms. In the spawning season the cutaneous glands of the male toad are gorged with venom, while those of the female are empty. Phisalix[162] has shown that at this period the venom of the female is accumulated in the eggs, which, if extracted from the abdomen at the moment of oviposition and dried _in vacuo_, give off in chloroform a product that has all the toxic properties of cutaneous venom (bufotalin and bufotenin). No trace of this poison is to be found in the tadpoles. B.--Lizards.