175 
escaping by rupture cannot, he believes, give rise to veritable 
pus at all. 
Teeth. — How to Study the Structure of the Teeth. By 
Professor S. P. Cutler. The Dental Register, Nov., 1868. 
In giving my processes for the investigation of the teeth, I 
would like very much for all who have instruments to follow 
me and give their individual results. This course, I main- 
tain, will at least reward any one, amateur or otherwise. In 
the first place, a good and reliable microscope will be pre- 
req\iisite. Secondly, a thorough practicable knowledge of 
the use of the instrument will be indispensable. 
To commence with the gum or soft pulp of a tooth. 
Formula No. 1. Procure a fresh pulp, sound and normal, 
and put this into alcohol (ordinary), and let it remain several 
days, when it becomes firm and tough. Then remove from 
the alcohol, and with a sharp razor slice into thin longitudinal 
sections, as thin as possible, observing the order in which 
they are cut. They are now ready for mounting, and should 
be mounted in the order in which they are cut. Mount in 
balsam, label and number. This specimen will show sections 
of blood-vessels, cellular tissue, and portions of nerve-fila- 
ments, commencing with the first slice, and follow the order 
of their mountings. 
Formula No. 2. Procure a fresh pulp as before, and treat 
same way in alcohol. Now remove, and commence at one 
end, and cut across at right angles to the pulp, and cut into 
thin slices, laying them aside in the order in which they 
were cut. Then mount, label, and number in the same order 
in which they were cut, as in the first process. 
Formula No. 3. This time cut a pulp, prepared as above 
directed, obliquely from end to end, observing the same 
angle through the entire pulp ; lay aside and mount as in 
the other cases. 
In the above specimens the filamental septum may be im- 
perfectly seen and studied, though not satisfactorily, as the 
cell contents will obscure the nerve fibrils, though not entirely 
so. For the above processes pulps of single teeth are prefer- 
able to begin with ; then the molars may be studied in the 
same way. When the pulp is removed from the alcohol it is 
white and tough, and should be cut and mounted as soon as 
possible, before it hardens too much. 
Formula No. 4. Procure a fresh pulp, and at once split it 
open from end to end ; then lay it on a slip of glass slightly 
coated with balsam pitch, and spread it out, after slightly 
rounding the glass (something like a hunter stretches his 
coon skin on a barrel to dry) ; then remove as much of the 
