New Species of Animal Concretions. 197 



tion of a very small quantity of resin, it entirely dissolved. 

 On distilling off the aether a semi-fluid viscid balsam of a 

 dark-red colour was left, which did not solidify at the tempe- 

 rature of the air, and acquired a pellicle on its surface by ex- 

 posure to air. When heated a portion of it was volatilized, 

 giving off at the same time the odour of melted caoutchouc. 

 It readily caught fire and burnt brightly ; its combustion was 

 unaccompanied by the slightest trace of the odour given out 

 by animal matter. It readily dissolved in caustic potass, and 

 the addition of an acid threw it down unchanged: it possessed 

 a biting acrid taste, felt particularly about the fauces ; by ex- 

 posure to the air it became a hard resin. 



When submitted to distillation in a small tube retort, no 

 oil passed over until the resin had acquired a temperature at 

 which it began to decompose, when an empyreumatic oil 

 came over : the quantity submitted to distillation was, how- 

 ever, too small to render the experiment quite satisfactory. 



The only conclusions that can be drawn from this analysis 

 are, that the principal constituent of the calculus is a vege- 

 table resin, which is characterized by crystallizing in the form 

 of six-sided prisms; that it is accompanied by a small quantity 

 of a soft resin, probably containing volatile oil ; that in ad- 

 dition to these it contains some other substances, as colouring 

 and extractive matter, the precise nature of which it is impos- 

 sible to determine, but which are doubtless also of vegetable 

 origin. 



M. Goebel detected in the concretion examined by him a 

 small quantity of the colouring matter of the bile. In no one 

 of the concretions examined was I able to satisfy myself of the 

 presence of that substance. It is probably therefore only an 

 accidental constituent. Its presence is however no proof of 

 their biliary origin, since the colouring matter and other con- 

 stituents of the bile are frequently found in hair-balls and 

 other concretions known to be formed in the intestine. 



Resino-bezoardic acid,when freed from the other substances 

 with which it is mixed in the calculus, possesses the following 

 properties : — It slowly dissolves in cold alcohol, more rapidly 

 in hot; according to Goebel, one part of resino-bezoardic 

 acid requires 29"4 of alcohol to dissolve it at 68° of Fahren- 

 heit and 6*5 of boiling alcohol ; in cold aether it is very spa- 

 ringly soluble, 444< parts being required, but only 47 when 

 boiling. Its alcoholic solution has an acid reaction, and the 

 resin is slowly deposited from it in the form of short six-sided 

 prisms. The crystals are exceedingly small ; they have ge- 

 nerally a yellow tint, but may be obtained quite colourless by 

 previously digesting the alcoholic solution with animal char- 



