384 Mr. Hatchett's Experiments on Zoophytes, 



Experiments were made separately, on each of the bodies 

 above enumerated; but, as I did not find any essential dif- 

 ference in the results, I shall include the whole under the 

 following observations. 



1. When distilled, a small portion of water, some carbonate 

 of ammoniac, a foetid empyreumatic oil, carbonated hydrogen 

 gas, carbonic acid gas, and prussic acid, were obtained. 



2. A spongy coal, of a gray metallic lustre, remained: this, 

 by incineration, afforded a very small residuum, which was not 

 always similar in quantity, even in portions of the same sub- 

 stance; for, 500 grains of tortoise-shell, taken from different 

 samples, afforded from £ of a grain to 3 grains of residuum, 

 which consisted of phosphate of lime, and phosphate of soda ; 

 sometimes also a little carbonate of lime was present ; but I do 

 not believe these to be essential ingredients. 



3. When boiled many days in distilled water, the substance 

 was softened ; and the water became slightly turbid with nitro- 

 muriate of tin; but no effect was produced by the tanning 

 principle. 



' 4. Muriatic and sulphuric acids had little effect, unless 

 heated; and the same was the case with nitric acid much 

 diluted, or in the state proper to extract and separate gelatin ; 

 but, if the immersion in the dilute acid was continued during 

 some weeks, the acid gradually acquired a yellow tinge, and, 

 when saturated with ammoniac, became of a deeper colour, 

 without having its transparency disturbed. 



5. The substance which had thus been long steeped in the 

 acid, was much softened, was become more transparent, and, 

 from being horny, was now more like a cartilaginous sub- 

 stance: when taken out of the acid, if it was immediately 



