CHATER PV. 
DISSECTION OF THE VASCULAR 
SYSTEM, 
InjecTIoN. fz dessecting the blood-vessels rt will be 
found most convenient to tnzect the arterves and vetns 
weth different colors, using coarse tngection, which wll 
not pass beyond the capillaries. Lhe injection materzal 
recommended 2s plaster of Paris. The dry powder 
should be mixed with water, stirring all the time, 
until the ligued has the consistency of a very thin 
paste, the coloring matter ts then added. This mtx- 
ture should not be made until rt zs ready to be used, 
since wt sets guickly. For the veins the best coloring 
matter to use ts a saturated agueous solution of 
Prussian blue; for the artertes, freshly prepared 
chromate of lead held in suspension in water. To 
prepare this latter make a 1% solution of am- 
montium or potasstum bichromate and a_ strong 
solution of acetate of lead, add the latter solution to 
the former, stirring all the while, until the bechromate 
solution 1s all prectpitated as yellow chromate of lead. 
Allow the ligued to stand until the precipitate settles 
to’ the bottom, then decant the supernatant ligued. 
Wash the precipitate several times with water, de- 
