lii INTRODUCTION. 



surface, which was supposed to shrink or withdraw from the matter 

 excreted. For, it has been asked, ' If the unvascular dentine be 

 the eifect of conversion of the vascular pulp, by what process is 



Then again, when Schwann admits the validity of an objection to the theory of the 

 ossification of the pulp, which I have proved to have no real weight, Mr. Nasmyth likewise, 

 admits its force in the words of his Author : — 



Schwannn, I, c. p. 126. Literary Gazette, I. c. p. 598. 



" Gegen die ansicht, dass die Zahn- " Against the theory that the dental 



substanz der verknocherte Theil der substance is the ossified portion of the 



Pulpa ist, hat man die leichte Trennbar- pulp, the facility ^vith which the one is 



keit beider von einander eingeworfen, separated from the other has been ad- 



und ich erkenne das Gewicht dieses duced ; and he (Mr. N.) allowed the 



Einwurfs wohl an." force of that objection." 



But the influence of the old doctrine of the discontinuity of the pulp with the calcified 

 layers of the ivory, was then dominant in the mind of the plagiarist of Schwann : he says in 

 the original part of the Report : — " Schwann regards the dental substance as the ossified pulp, 

 whilst Mr. N.'s observations lead him to conclude that the cells of the ivory are altogether a 

 distinct formation." — Literary Gazette, p. 598. Mr. N., in fact, exaggerated at Birmingham 

 every statement of Schwann which led towards the doctrine of ossification of the pulp in order 

 that he might refute him. Thus, according to the * Literary Gazette,' he makes Schwann 

 " regard the dental pulp as a simple cartilage ;" he drags the dubious expression of his 

 inclination towards the ancient doctrine of the tooth being the ossified pulp, from a remote 

 part of Schwann's treatise, converts it into a positive aflBrmation, and places it in juxta-position 

 with the statement of Schwann's ideas of the relation between the dental pulp and cartilage, 

 in order to formally contradict the conclusions of the original German observer, who, Mr. 

 Nasmyth says : " starts with a ready-made hypothesis, and founds his opinion rather on the ob- 

 servations of others, and on the inferences he draws from them, than on his own actual 

 research." — Literary Gazette, loc. cit. p. 598. 



Thus, whatever influence the observations of Dr. Schwann might have had in drawing 

 Physiologists back towards the old doctrine expressed by Raw and Blake, must have been 

 greatly deteriorated by those who might place any confidence in the labours of Mr. Nasmyth, 

 on which his communication to the British Association, in August 1839 was based. The 

 right interpretation of Schwann's observations, required, in fact, a new series of researches, and 

 that interpretation only became obvious to Mr. Nasmyth, after the pubhcation of my 

 "New Theory of Dental Development," in the ' Compte Rendu' of December, 1839- 



