ON DISEASES OF THE MOUTH. 5I7 



and fage, adding a fmall quantity of diftilled 



vinegar. 



Dr. Darwin aflcs, " does the enamel (upon 

 " human teeth) grow again when it has been 

 " perforated or abraded ?" I have tried to reftore 

 it for a confiderable number of years together; 

 and if any thing can poffibly effe6l fucli end 

 (which I much doubt) I think it is the conftant 

 ufe of the bark, w^iich I have ever found the 

 bed dentrifice. Much will depend upon the 

 age of the fubjeft. About ten years ago, a man 

 whom I chanced to know, publiflied a dentrifice 

 under the title of Eaftern Tooth-powder, or 

 fome fuch name, the bafis of which was japan 

 earth, and which inftead of polifhing, aftually 

 abraded the enamel from the teeth of thoufands, 

 and of my own among the reft of the gulls. The 

 conftant ufe of bark tinges the teeth with a yel- 

 low hue. Strong acids have been frequently 

 recommended : they are certain deftruftion to 

 the enamel. I know of nothing equal to foap, 

 both for the cleanftng and prefervation of the 

 teeth. 



I am again called upon by. Mr. Blaine (vol. ii. 

 p. 93) and, as ufual, upon a moft important oc- 

 . cafion, no lefs than that of my having propa- 

 gated that momentous error of the old fchool, 

 the excifion of excrefcences under the tongue of 

 the horfe, called barbs or paps. In a long and 

 windy note, this writer obferves : " Perfons who 



profels 



