%>J2 Mr. Hatchett's Experiments on Zoophytes, 



assertion of a considerable hair merchant in this metropolis,* 

 who, during a long experience of upwards of forty years, has 

 always found, that hair of the first named quality cannot be 

 boiled an equal time with those last mentioned, without suffer- 

 ing material injury in strength and flexibility. 



Feather, digested in boiling distilled water, during ten or 

 twelve days, did not afford any trace of gelatin by the test of 

 the tanning principle ; but nitro-muriate of tin produced a faint 

 white cloud. 



The same was observed when quill was thus examined. 

 - Shavings and pieces of the horns of different animals were 

 next subjected to experiment, and all afforded small quantities 

 of gelatin, which was precipitated by the tanning principle, and 

 by nitro-muriate of tin ; and it was generally observed, that the 

 more flexible horns yielded the largest quantity of gelatin, with 

 the greatest ease ; and, (like the substances already mentioned,) 

 when deprived of it, and suffered to dry spontaneously in the 

 air, they became more rigid, and were easily broken. 



The horns which I mean, are those of the ox, ram, goat, and 

 chamois, which, in my former paper I considered, as I do now, 

 to be perfectly distinct from the nature of stag's or buck's horn ; 

 for this last is as different from the former in chemical compo- 

 sition, as it is in construction : like bone, it affords much phos- 

 phate of lime, and, like bone, it affords a large quantity of gela- 

 tin ; and it is not a little remarkable, that phosphate of lime is 

 generally accompanied by gelatin, as in stag's horn, bone, 

 ivory, &c. on the contrary, when carbonate of lime is the hard- 

 ening substance, as in shells, madrepores and millepores, no 

 gelatin can be discovered ; for I have frequently digested these 



* John Collick, Esq. of St. Martin's Lane. 



