54 THe Microscope. 
BEALE’S PRUSSIAN BLUE. 
This is used for making transparent injections, and certainly 
for exhibiting fine vessels under high powers it has no equal. 
The bright color is permanently retained if the hardening 
reagents be made slightly acid; or if preserved in a fluid, this 
also should have a little free acid added to it. It is prepared as 
follows: 
Common glycerine------------ see 8 ee 1 ounce, 
Aleoholsce <a. eben 1 ounce. 
Ferrocyanide of potassium ---------------- 12 grains. 
Tincture ‘perchloride irom 22_ 22> 1 drachm. 
‘Waters. 2 3220-41 8S ee eee 4 ounces. 
The ferrocyanide of potassium is to be dissolved in one 
ounce of the water and glycerine, and the tincture of iron 
(muriated tincture of iron) added to another ounce. Thes® 
solutions should be mixed together very gradually and well 
shaken in a bottle. The iron being added to the solution of 
the ferrocyanide of potassium. When thoroughly mixed, the 
solutions should produce a dark blue mixture, in which no pre- 
cipitate or flocculi are observable. Next the spirit and the 
water are to be added very gradually, the mixture being con- 
stantly shaken in a large stoppered bottle. In cases, in-which 
a very fine injection is to be made for examination with the 
highest powers, half the quantity of iron and ferrocyanide of 
potassium may be used. 
BEALE’S ACID CARMINE INJECTING FLUID. 
Carmine ici: os - 22-2 vew. Se LEU 5 grains. 
Glycerine, with 8 or 10 drops of acetic or 
hydrochloric acid- -.------------- 144 ounce. 
Glycerine 2-20. 5-4 e eee ee 1 ounce. 
AMleOn Ose 22-2 = <P aS cee ee eee 2 drachms. 
ATI AS es ee ee a few drops. 
Mix the carmine with a few drops of water and, when well 
incorporated, add about five drops of liquor ammoniz. To this 
dark-red solution about hatf an ounce of the glycerine is to be 
added, and the whole well shaken in a bottle. Next, very 
gradually pour in the acid glycerine, frequently shaking the 
bottle during admixture. Test the mixture with blue litmus 
paper, and if not of a very decidedly acid reaction, a few drops 
