ANIMAL POISONS. 541 



whole, with those of Dr Davy, though in some circumstances 

 they differ. He found that when exposed to the air it soon be- 

 came solid, and that if it had been put into a watch-glass it might 

 in a few minutes be taken off under the form of transparent 

 scales. It was exceedingly acrid, both when liquid and solid, 

 and reacted strongly as an acid. With water it formed an emul- 

 sion. Cold alcohol had little action on it ; but it dissolved a 

 portion when assisted by heat, and assumed a fawn-colour. The 

 portion undissolved was white and destitute of taste and smell. 

 It resembled, according to Pelletier, the gelatinous membranes. 



The alcoholic solution scarcely reddened litmus- paper, and lost 

 that property entirely when evaporated. As the alcohol was 

 driven off an oily matter separated, which became solid on cool- 

 ing. This matter was insoluble in water, little soluble in ether ; 

 but very soluble in alcohol. Its taste was very bitter ; but it was 

 neither acrid nor caustic. It reacted slightly as an alkali. The 

 acid of the poison of the toad appears from Pelletier's experi- 

 ments to be very volatile and only partially combined with a base- 

 Hence probably the reason why it was not detected by Dr Davy 



The gelatinous matter of the poison was insoluble in cold wa- 

 ter ; but soluble in hot water, to which it communicated a gela- 

 tinous consistence. But, as it was neither precipitated by chlo- 

 rine nor by infusion of nut-galls, it is obvious that it was a differ- 

 ent substance from either collin or chondrin. 



3. The venom of the bee and the wasp is a liquid contained in 

 a small vesicle forced through the hollow tube of the sting into 

 the wound inflicted by that instrument.* From the experiments 

 of Fontana we learn that it bears a striking resemblance to the 

 poison of the viper. That of the bee is much longer in drying 

 when exposed to the air than the venom of the wasp. 



4. The poison of the scorpion resembles that of the viper also. 

 But its taste is hot and acrid, which is the case also with the ve- 

 nom of the bee and the wasp. 



5. No experiments upon which we can rely have been made 

 upon the poison of the spider tribe. From the rapidity with 

 which 'these animals destroy their prey, and even one another, 

 we cannot doubt that their poison is sufficiently virulent. f 



* See a curious account of the structure of the sting by Dr Hooke in his Mi- 

 crographia. 



f Dr Mead's romantic account of the bite of the tarantula will entertain the 

 reader. See Mead on Poisons, p. 57. 



