376 ANATOMICAL PREPARATIONS 
other ingredients are added. This method prevents any 
effervefcence, which often happens when there is too great 
a fire, or when all the ingredients are mingled together 
before the colouring powders are added, efpecially the two 
laft. The quantity is judged of by trial. 
Of the proper MENSTRUUM. 
I now pafs to the third head, viz. to confider what fub- 
ftances will anfwer, for confuming all the parts furround- 
ing the injetion, and leaving the matter in the veflels 
themfelves untouched. . 
The beft I have yet tried is the concentrated fuming 
acid of marine falt, which comes over in the diftillation 
employed in the procefs for making glaubers falt; it 
fhould not be diluted with water, nor be dulcified, other- 
wife it becomes too weak to anfwer the purpofe, or at leaft 
the time required for compleating the corrofion is thereby 
protracted beyond what is needful. 
The concentrated acids of vitriol and of nitre, are no lefs 
powerful to deftroy all the animal fubftance, furrounding 
the injected veflels, but the obje€tion to which, from feve- 
ral trials, they appear to be liable, is that they are fup- 
pofed to crifp the veflels ; at leaft the fpirit of fea-falt has 
been moft ufed,,and concluded to be the leaft exception- 
able menftruum for this operation. 
Such were the fentiments I communicated, in my me- 
moir to the royal academy of furgery at Paris in the year 
1764, fince which, Monf. Siie, royal profeflor of anatomy 
in the f{chools of furgery, and in the royal academy of 
painting and fculpture at Paris, having honoured my com- 
munication to the abovementioned academy, with a fec- 
tion in his treatife entitled Anthropotomie, chap. 2. fect. 
25. from page 70 to page 84; after acknowledging that 
he reccived the art of making thofe preparations from me, 
thus adds. ‘ Since that time my nephew and I, having 
worked at them a great deal, and with abundant fuc- 
cefs, 
