Masticating Surface of Molars and Bicuspids. 183 



to the retention of fluids and semi-solids, which undergoing decom- 

 position would speedily destroy the thin septum of enamel covering 

 the dentine. In the latter tissue, closely contiguous to the enamel, 

 a number of black spaces (the 

 interglobular spaces) will be 

 seen. Here again is located 

 defective structure and a 

 prolific predisposing cause of 

 decay. The large space re- 

 presents a carious cavity com- 

 mencing on the approximal 

 side of the tooth. 



In a paper read before the 

 American Dental Association 

 at the meeting held in Boston, 

 August, 1866,* giving the 

 results of a personal examina- 

 tion of the interglobular 

 spaces, I remarked, "As 

 evidence of the practical bear- 

 ings of these investigations, it 

 may be well to direct attention 

 to the fact that the existence 

 of the spaces in teeth which have completed their growth must 

 be regarded as an abnormal condition, predisposing such teeth to 

 decay, and that when either by mechanical action, as by a fall or 

 blow, or by the penetration of external caries, such spaces are 

 reached, the disease here would run riot ; hence the importance of 

 care on the part of patients and operators to have the most minute 

 cavities filled ; for though reached only through a microscopical 

 opening, the result would be the same, while, if protected from the 

 action of external influences or the exciting causes of decay, this 

 predisposition might remain dormant for a lifetime, as is sometimes 

 the case with other diseases." 



With no disposition to revive a useless discussion, or to dwell 

 upon the very unreasonable, not to say absurd, objections and 

 denials which were ofi'ered to the communication by doubtless well- 

 meaning but mistaken men, at the same time I cannot but regret 

 that they influenced the opinions of others who, reposing implicit 

 faith in their acuteness and judgment, very naturally regarded the 

 objections as of a valid character, until an opportunity for observa- 

 tion convinced them to the contrary. Such was the case with the 

 gentleman who handed to me the specimen under consideration. 



It is to be hoped that the illustration ofi'ered will teach a 

 valuable lesson to those who have been in the habit of dismissing 

 * 'Dental Cosmos,' vol. viii., p. 113. 



