372 ANATOMICAL PREPARATIONS 
My well meant intention of marking the rife and pro-= 
grefs of this art, and of exciting an emulation in my 
countrymen to profecute and improve it, will, I hope, not 
enly excufe but juftify both the matter and length of my 
introduction. 
Thefe preliminaries being thus fettled, I now proceed 
to the main obje&t of this communication. Without ex- 
patiating upon the advantages that will attend an accurate 
knowledge of this art, for the fake of perfpicuity I fhall 
here reftri&t myfelf to laying the following obfervations 
before you, reduced to general heads, in as few words, 
and in as concife a manner as I am able. They may be 
ufeful to thofe who with to put them in praétice, and will 
perhaps give occafion to perfons who are curious in making 
experiments in anatomy, to lizht up fome new difcovery. 
The art of making anatomical preparations by corrofi- 
on, depends on the following principles. 
1. We ought for the matter of injection to make ufe of 
a fubftance that is pofleffed of a fuitable degree of confift- 
ence, and fine enough to penetrate into the minuteft vef- 
fels, and which at the fame time has fuch a firmnefs of 
texture as not to alter with the changes of the temperature 
of the atmofphere, that is, it ought not to be fubje& to 
melt with the fummer’s heat, nor to break down from its 
brittlenefs on being gently handled in the winter. 
2. The colours to be employed for fake of diftinguifh- 
ing the different orders of veflels, whether arterial, venal, 
tracheal or others, ought to be of fuch a nature as not to 
be changed upon application of the menftruum. 
3. We ought to make ufe of a menftruum that is capa- 
ble of confuming the mufcular, parenchymatous, cellular 
or fatty parts that furround the veflels, without affecting 
the fubftance that we ufe for injection to fill the veffels. 
4. Care and addrefs are neceflary in the perfon who 
makes the injection. 
5. Laftly, great attention is requifite in removing the 
loofe and corroded parts, and in feparating them from the 
injected 
