1914} 'Alfred P. Lothrop 313 



method was employed, with exceptional advantage.*^ A small 

 amount of water was kept on the bottom of the Chamber and the 

 " artificial jaw " was supported at a level therein, on flat pieces of 

 cork. By maintaining closure with the glass Hd, the atmosphere in 

 the Chamber above the teeth was kept saturated with water, and the 

 sahva on and around the teeth was prevented from evaporating. 

 The conditions for bacterial activity were especially favorable he- 

 cause of the Stagnation of the fluid. 



The conditions of these experiments were such as to favor (a) 

 the maximum destructive effect, if any, of the hquids iised as den- 

 tifrices, and {h) the minimum protective influence of the saHva. 

 The normal conditions in the mouth, it seems to us, would permit 

 less destructive activity by the acid (if there was any such action), 

 and would possess greater protective potential. 



One set of seven teeth has been treated twice daily, since June 

 6, 19 13 (six months), with vinegar (apple eider) diluted, half and 

 half, with water; a second set of nine teeth has been simultaneously 

 treated with a populär, slightly alkaline, antiseptic dentifrice. 



These two sets of teeth were exhibited and examined at a meet- 

 ing of the First District Dental Society of the State of New York, 

 at the N. Y. Academy of Medicine, on Oct. 6, 1913. Drs. Merritt 

 and Linton reported (then, orally; again, by letter on Dec. 2) that 

 they were unable to detect any change, whatever, in these teeth as 

 a result of the treatments, except that the filling of oxy-phosphate 

 of zinc in one of the teeth, in the series treated with vinegar, was 

 "very considerably washed out . . . due, probably, to the abrasive 

 action of the brush and partly to the solvent action of acid in the 

 vinegar" (Dr. Merritt). ^^ 



The proposed use of dilute vinegar and food-acid media in 

 general, as dentifrices, appears to be devoid of harmful influences. 

 Our study in this connection is in progress. 



119. The organic constituents of raw and bumed soils. 

 Arthur W. Thomas. Raw soil supplied through the kindness of 



^^ Gies: Proceedings of the Society for Experimental Biology and Medicine, 

 1908, vi, p. 27. The apparatus referred to consists of a rectangular heavy-glass 

 box, with an adjustable glass lid — in effect, a tall, rectangular box open at one 

 broad side instead of at the top, and resting on the opposite side. 



1'^ Lothrop and Gies : Journal of the Allied Dental Societies, 1913, viii, p. 304. 



