382 Scientific Intelligence — Anthropology. 



the teeth, are got rid of by being discharged through the ex- 

 ternal orifice corresponding to the mouth. There are other solid 

 plates of the epidermic portion of the stomach, which are not 

 of a shape calculated to irritate the new and tender epidermis, 

 and consequently they can be retained with impunity, and are 

 destined to perform a new and curious function, for according 

 to Baer, these plates, for some time preparatory to the act of 

 casting the shells, rapidly increase in weight and in solidity, so 

 as at the period we are speaking they may be considered as form- 

 ing considerable reservoirs of earthy matter, to be gradually 

 dissolved and digested in the newly lined stomach, at the very 

 time earthy matter is required by the animal for the formation 

 of its new shell. These plates are popularly called crab-stones, 

 and when submitted to the digestive process soon lose their 

 roughness, and become smooth and polished before they are en- 

 tirely dissolved. These crab-stones are chiefly composed of 

 carbonate of lime, and Baer has proved, by repeated analysis, 

 that the fluid contents of a crab's stomach contain (at the time 

 these stones are in them) a considerable portion of lime, carbonic 

 acid, and muriatic acid. It is interesting to observe, that the 

 chemical investigations of Dulk render it highly probable, that 

 the chief solvent in the crab's stomach is the same acid which 

 plays so important a part in human digestion and in dyspepsia, 

 y'lz.Jree muriatic acid.^^Dublin Medical Journal 



ANTHEOPOLOGY. 



20. Dreadful Effects of the Immoderate Use of Coca.— Dr 

 Poeppig, in his Travels having mentioned the Coca plantations, 

 gives a very long account of the remarkable plant, which has now 

 become an indispensable necessary of life amongst the Indians of 

 the Andes; and, as an article very extensively cultivated, deserves 

 great attention. The coca {Erythroxyhn Coca, Lam.) is a bush 

 from six to eight feet high, somewhat like a blackthorn, which it 

 resembles in its numerous small white blossoms, and the lively 

 green of the leaves. These leaves, which are gathered and care- 

 fully dried, are an article of brisk trade, and the use of them is 

 as old as the first knowledge of the history of Peru. It is a 

 stimulant which acts upon the nerves in the same manner as 

 opium. Unhappily, the use of it has degenerated into a very 



