I 



On the Operation of Medicines. 205 



of rendering even ivory itfelf foft and fragile. 

 How far it would produce fuch an efFeft on the 

 bones of a living body, if ufed as the chief 

 article of diet, we have no experience on which 

 to ground any fatisfadory conclufion. The 

 peafantry, in the mountainous parts of this coun- 

 ty, who live on oat meal, are peculiarly liable 

 to the itch, and to other cutaneous eruptions. 

 Thefe have fometimes been afcribed to ob- 

 ftruded perfpiration. But fuch obftruftion is 

 itfelf only a concomitant effeft of fome quality 

 in the oat meal injurious to the fkin. 



Sulphur, whether externally or internally ufed, 

 produces a cure in the itch. In each way, there- 

 fore, we may prefume its operation to be fimilar. 

 But when taken into the ftomach, there can be 

 no doubt that it undergoes a change in the 

 modification of its parts, and that it does not 

 circulate through the blood veflels either in the 

 form, or with the properties of fulphur. Yet 

 when conveyed to the furface of the body, it 

 appears evidently to recover its original powers; 

 communicating its peculiar odour to the per- 

 fpiration, tinging filver, and curing cutaneous 

 defoedations *. The fame holds true of the 



vitriolic 



* Biftiop Watfon, in his Chemical Eflays, warns thofe 

 who ufe cofmetic lotions containing cerufTe, to forbear 

 from them at Harrowgate, Moffat, or other places where 

 they drink fulphurated waters, *' left they fhould be in 



" the 



