39 THE AMERICAN MONTHLY [Febuuraes 
If the steps in this method are carefully followed out success is certain; and 
it is, without exception, the method for tracing nerve fibres or demonstrating 
nerve lesions.—J/edical News, Nov. 6, 1886. 
Injections. 
The following directions are given by Mr. V. M. Latham, F. M. S. :—* 
1. Prussian blue fluid.—Glycerin 1 oz., alcohol 1 oz., ferrocyanide of 
potassium 12 grains, tinctr. of perchloride of iron 1 drachm, water 4 oz. 
Mix the glycerin, water, and alcohol, and divide it into two equal parts. In 
one part (a) dissolve the ferrocyanide, and to the other part (4) add the tinct- 
ure perchloride. Add (6) very gradually to (a), the mixture being well 
shaken after each addition of the iron solution; keep in a stoppered bottle, 
and shake well before using. 
2. Turnball’s blue.—Dissolve 10 grains of pure iron sulphate in 1 oz. 
glycerin, or better, a little distilled water, and add 1 oz. glycerin and 32 grains 
ferrocyanide of potassium in another oz. of glycerin. Add the iron solution 
gradually to the cyanide, with constant agitation. To the deep-blue fluid 
which results, add 1 oz. glycerin, 1 oz. alcohol, and 4 oz. water. This 
injection will not fade so soon as the Prussian blue, hence its advantage. 
3. Bruckle’s soluble Prussian blue.—(qa@) Ferrocyanide of potassium, 
217 grammes, in 1,000 c.c. distilled water. (6) Perchloride of iron, 10 gms. 
in 2,000 c.c. distilled water. (c) Saturated solution of sulphate of soda. Mix 
one part of a with one part of c, and one part of 4 with one part of c; add 
mixture @ c to mixture 6 c; allow the mixture to stand about three hours (or 
longer, if necessary). Collect the deposit on a filter, and wash three or four 
times a day with distilled water. When the water carries blue color through 
with it, discontinue the washing, and dry. The powder thus prepared must 
be dissolved in distilled water, and mixed with gelatin to form a firm jelly.t 
4. Beall’s acid carmine.—Carmine 5 grains, glycerin with 8 or 10 drops 
acetic or hydrochloric acid 4 oz. (acetic is preferred), glycerin 1 0z., alcohol 
2 drachms, water 6 drachms, a few drops of ammonia. Mix the carmine with 
the water, and add ammonia (5 drops). To the dark red solution add $ oz. 
glycerin, and shake well. Add gradually, with frequent shaking, the acid 
glycerin. Test, and if the reaction is not distinctly acid, add more acid 
glycerin till it becomes so. Now add alcohol and water very gradually, with 
frequent shaking. This is one of the very best injection fluids ever recom- 
mended. It may be kept ready, and very rapid injections made with it. 
5. Asphalt and chloroform.—Prof. Ludwig has employed, in studying 
the bile ducts, a fluid composed of asphalt dissolved in chloroform. The 
chloroform flows well, being extremely mobile, then readily evaporates, leav- 
ing a solid black mass in the vessels. 
6. Alcannin and turpentine.—Ludwig used for the lymphatics a solution 
of alcannin in turpentine or chloroform. The solution is of a bright red color ; 
it flows easily. If chloroform solution be used, the chloroform evaporates 
readily, and leaves the alcannin in the vessels. 
7. Silver nitrate for blood vessels. Stun a frog by a blow upon the head, 
expose the heart, strip off its apex, and allow it to bleed thoroughly. Push 
a canula from the ventricle into the aorta, and inject a stream of distilled water 
to wash out chlorides. Follow this with a one-quarter of one per cent. solu- 
tion of silver nitrate, and allow to remain for eight or ten minutes, then wash 
* Yournal of Microscopy, vol. vi (87), p. 41. 
+ This method, which is the one given in Burdon Sanderson’s Physiological Text-Book, has never given satis- 
faction, after repeated trial, in our own experience ; the difficulty arose in getting the precipitate properly washed. 
