PHYSIOLOGICAL DEMONSTRATION OF TEETH. 535 
disease, whether “ medical” or “ surgical” amongst his fellow- 
countrymen, to pass a complete and proper examination in 
all branches of his profession. That, having passed such an 
examination, he may practise in any or every department of 
his profession that he may choose ; that all shall have equal 
rights and privileges ; and that the public and the profession 
shall be alike protected from the myriads of impostors, cheats^ 
and knaves, who, professing to be members of a noble pro- 
fession, bring not only disgrace upon that, but inflict irre- 
parable injury upon their dupes, the public. — Lancet , 28 th 
May , 1853. 
THE PHYSIOLOGICAL DEMONSTRATION OF THE TEETH. 
Dr. Boon Hayes thus describes the structure of these 
organs : 
“ In the first place, observe the pulpal cavity, which is to 
the tooth what the medullary cavity is to bone, and which 
originates in the same way. Into it pass an artery, vein, and 
nerve ; and these ramify upon the pulpal surface, the artery 
carrying blood to the dentinal tubuli, whence the liquor 
sanguinis (not blood-corpuscles) proceeds, to the nourishment 
of this apparently inorganic mass. 
“ In the teeth of some animals, this cavity seems to send 
off diverticula between the dentinal tubuli, as if for the pur- 
pose of supplying them with more vascularity. On to the 
avails of the pulpal cavity the dentinal tubes open, and 
thence radiate to the enamel superiorly, and the crusta 
petrosa inferiorly. 
“ I think it would not be difficult to prove that caries of 
teeth more frequently proceeds from inflammation com- 
mencing in this cavity than from any other cause. But I 
shall refer to this at another period. 
“The dentine, or ivory of teeth, is their essential com- 
ponent ; it consists of tubes which lie, for the most part, in 
a parallel direction, and intertubular substance. When exa- 
mined with a high power, and by transmitted light, the 
tubuli appear dark. 
“ Now, these tubuli are very, very much more minute in 
diameter than the blood-globule ; hence the liquor sanguinis 
alone can permeate them for their nourishment; so that teeth 
are in the same condition as bone in this respect. The den- 
tinal tubes, of course, appear dark, and the lighter and appa- 
rently broader masses are the real substance of the dentine. 
