Royal Society. 545 



of a medal of the value of fifty guineas, to be bestowed as hono- 

 rary distinctions by the President and Council, on the authors of 

 such new discoveries as they may deem worthy of the award ; and 

 in such manner as shall best promote the objects for which the 

 Royal Society was instituted ; and the interests of science in 

 general. 



Dr. J. R. Johnson, F.L.S. elected into the Society in 1817, 

 and whose name had then been inserted in its printed lists, was 

 admitted a Fellow of the Society; and the Croonian Lecture^ 

 by Sir E. Home, was read. The subject of this lecture was the 

 Structure of Muscular Fibre. 



Dec. 22.— Gideon Mantell, Esq. F.L. & G.S. was admitted a 

 Fellow of the Society ; and the following papers were read : 



On the Poison of the Comtnon Toad; by J. Davy, M.D. F.R.S. 

 The popular belief in the venomous nature of the Toad, Dr. Davy 

 states, though of great antiquity, has been rejected as a vulgar 

 prejudice by modern naturalists, decidedly so by Cuvier; but 

 like many other long-received and prevalent opinions, it is a true 

 one, and the denial of it by philosophers has resulted from super- 

 ficial examination. Dr. D. found the venomous matter to be 

 contained in follicles, chiefly in the cutis vera, and about the head 

 and shoulders, but also distributed generally over the body, and 

 even on the extremities. On the application of pressure, this 

 fluid exudes, or even spirts out to a considerable distance, and 

 may be collected in a sufficient quantity for examination. It is 

 extremely acrid when applied io the tongue, resembling the ex- 

 tract of aconite in this respect, and it even acts upon the hands. 

 It is soluble, with a small residuum, in water, and in alcohol, and 

 the solutions are not affected by those of acetate of lead and 

 corrosive sublimate. On solution in ammonia, it continues acrid; 

 it dissolves in nitric acid, to which it imparts a purple colour. By 

 combination with potash or soda, it is rendered less acrid, appa- 

 rently by partial decomposition. As left by evaporation of its 

 aqueous or alcoholic solutions, it is highly inflammable ; and the 

 residuary matter, which appears to give it consistence, seems to be 

 albumen. Though more acrid than the poison of the most veno- 



VOL. II. 2 M 



