By CORROSION. 369 
ford, which I further improved by praétice at Paris with 
Monf. Siie, to whom I am wholly indebted for my know- 
ledge of anatomical preparations in wax. 
The kind of preparations of thofe parts of the animal 
body which admit of it that I now propofe to explain, 
namely by injetion and corrofion, exceeds in beauty, 
nicety and ufefulnefs, that which is commonly called dif- 
fection. 
In fact, m this latter, we can trace nature but very im- 
perfe@tly, becaufe by diffection, the larger veffels only are 
preferved from the knife, and for the moft part all the 
{maller are unavoidably cut away. 
On the contrary, in anatomical preparations by corrofi- 
on, even the very {mall veflels may be kept entire, and 
we can fee, at a caft of the eye, the courfe and diftributi- 
on of all the vafcular fyftem even to the fize of an hair, 
called capillary veffels, and thofe too difengaged from the 
furrounding parts, which otherwife wholly conceal, or 
make them difficult to be perceived. It is impoffible that 
with only the affiftance of a diflecting knife, any perfon 
fhould be able to lay open to view all thofe {maller veffels, 
however fkilful and experienced the hand may be that 
directs it. The exact and perfe&t imitation of nature 
which this fort of preparations prefents, the eafe with 
which they are made, and their extraordinary beauty and 
neatnefs, render a knowledge of this art fo much the: 
more defirable. 
The art of injefting the very fine veffels of the body 
with common injection, was well known to the celebrated 
Ruyfch, the moft famous anatomift, im that way, of any 
living in Europe in his day; and therefore it has been 
fometimes called the Ruyfchian art, but it fell fhort of the 
one I now undertake to explain, becaufe in his prepara- 
tions the minute veffels only become vifible, fo far as 
the fubftance through which they proceed was tranfpa- 
rent, but our art extends to the removal of every fur- 
rounding 
