AND HOW TO USE IT. 43 



under high powers, being too faint : — Ferridcyanide of potassium, 

 lo grains ; sulphate of iron, 5 grains ; water, i ounce ; glycerine, 

 2 ounces ; alcohol, i drachm. The advantage of this injection 

 over Prussian blue is that the colour does not fade in course of 

 time. (Beale.) 



Bruckle's Soluble Prussian Blue. — {a) Ferrocyanide of potas- 

 sium, 217 grammes, dissolved in one litre of distilled water, {b) 

 Perchloride of iron, 10 grammes, dissolved in 2 litres of distilled 

 water, {c) A cold saturated solution of sulphate of soda. Mix 

 one part of a with one part of c, and mix one part of b with one 

 part of c, add the mixture a c to the mixture b c, and allow the 

 mixture thus formed to stand about three hours (longer if 

 necessary), collect the deposit on a filter. Wash the deposit three 

 or four times a day for a week by pouring over it small quantities 

 of distilled water. The washing must be discontinued as soon as 

 the water which runs through is quite blue ; and the powder thus 

 prepared must be dissolved in distilled water, and mixed with 

 sufficient gelatine to form a firm jelly. 



Dr. Beale' s Acid Carmine Fluid.— Carmine, 5 grains ; gly- 

 cerine, with eight or ten drops of acetic or hydrochloric acid, 

 J ounce ] glycerine, i ounce ; alcohol, 2 drachms ; water, 

 6 drachms ; ammonia, a few drops. Mix the carmine with a few 

 drops of water, and when well incorporated, add about five drops 

 of liquor ammonia. To this dark red solution, about | 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 more acid must be added to the remainder of the glycerine, 

 and mixed as before. Lastly, mix the alcohol and water very 

 gradually, shaking the bottle thoroughly after each successive 

 portion till the whole is mixed. This may be kept ready, and 

 very rapid injections made with it. It is without doubt one of the 

 very best fluids ever devised. It is most useful for injecting such 

 lower forms of animal life as insects, shell-fish, snails, and small 

 fishes. Acetic acid is to be preferred to hydrochloric for the pur- 

 pose of acidifying the solution. The object in adding acid to 



