416 Analysis of the Excrements of the Boa Constrictor. [June, 



muriate of platinum. This alkali, as well as the ammonia, I con- 

 sidered as combined with the uric acid, because no effervescence 

 was produced on the addition of muriatic acid. 



I obtained these excrements from Mr. Lean, jun. and on ascer- 

 taining their composition, went to see the animal said to be the 

 boa constrictor, exhibited near Exeter Change, in order to learn a 

 few particulars of its mode of feeding, &c. This animal is a 

 young one, and, according to the keepers statement, about 16 feet 

 long. It is fed about once a month only, when a living rabbit, or 

 sometimes two small ones, are exposed within its reach, vvhich, 

 after some time, it seizes, destroys, and swallows, in the manner 

 peculiar to these serpents. The excrements are discharged at 

 periods of about 8 or 10 days, in a softish state, about the con- 

 sistence of stiff dough ; but soon become hard and friable on ex- 

 posure to the air. They are in the form of roundish scybalae, and 

 on their surface there is often a yellowish substance, sometimes in 

 a crystallized state, which crystals I have found to be urate of am- 

 monia, tinged whh a little colouring matter. These are the only 

 kind of feeces, or excrements, observed to come from the animal. 

 I obtained a portion of them a few hours after they had been dis- 

 chaiged, which had all the characters and properties of those above 

 described, whif h I received from Mr. Lean. 



As far as 1 know, uric acid has not been observed to be formed 

 by this class of animals. Dr. Wollaston has found that birds pro- 

 duce more of this principle when fed on animal matters ; and 

 Fourcroy, Vauquelin, and Klaproth, found a large proportion of it 

 in the excrem'ents of a bird called guano, brought from the South 

 Sea Islands.* It is certainly a very extraordinary thing, that nearly 

 the whole of the food taken by tliis animal should be converted 

 into this substance. May it not proceed from disease arising from 

 the unnatural state in which it is kept ? 



Licjuor Amnii of a Cow, 



This had been taken from the uterus of an animal slaughtered 

 in an early period of her gestation. It was of a yellowish colour, 

 and had the appearance of very minute shining particles floating in 

 it. .Smell fragrant, something like that of new milk or butter. 

 Taste bland and sweetish, like fresh whey. Foamed a good deal 

 when shaken. Did not affect litmus or turmeric papers. Sp. gr. 

 1-013. 



My attention was particularly directed to the principle found in 

 this fluid by Vauquelin and Buniva, and called by them mnmolic 

 acid. I could not, liowcver, discover the least traces of a similar 

 principle ; but it comained a very sensible quantity of the sugar of 

 milk, which separated in crystals from it, when it had been con- 

 centrated by evaporation. It coagulated partially by heat, and 



* I quote from RerTflius's View of the Progress and present State of Animal 

 Ciieniistry. P. lOS. 108. 



