AND HOW TO USE IT. 45 



solution by means of 90 per cent, alcohol. The colouring matter 

 is thus precipitated in a state of most extreme fineness, and a 

 completely neutral fluid is obtained. 



White Fluid. — This is very finely granular, and is capable of 

 being combined with a blue, if it be desired to inject the arteries 

 and veins separately. The salt sulphate of baryta is re-precipi- 

 tated from a cold saturated solution of 4 ounces of chloride of 

 barium, by adding, dropwise, sulphuric acid. After standing for 

 some time (twelve to twenty-four hours) in a tall cylindrical glass 

 vessel, it is deposited at the bottom. About half the fluid, which 

 has again become clear, is now to be poured off, and the 

 remainder, well shaken up, is to be combined with a mixture of 

 one ounce each of alcohol and glycerine. It is distinguished for 

 its great permeability, and is very good for lymph passages and 

 glandular canals. It may be kept for months without alteration, 

 and should be instantly at hand. The requisite quantity for an 

 injection is poured into a porcelain dish, and it is then ready for use. 



Brownisli-Red Cold Flowing Mass, which is obtained by pre- 

 cipitation from a solution of the chromate of copper, with 

 ferrocyanide of potassium. Chromate of copper is obtained by 

 digesting equivalent portions of sulphate of copper with chromate 

 of potash, and washing out the brown precipitate. The latter 

 readily dissolves in chromic acid in excess, and may be precipi- 

 tated from the diluted solution, by means of ferrocyanide of 

 potassium, in the form of an extremely fine brownish-red sediment 

 of ferrocyanide of copper. It may be at once injected, without 

 further addition than the solution of bichromate of potash, which 

 has been formed, and thus, at the same time, serve as a medium 

 for hardening the same. It is very useful for spleen. 



Soluble Prussian Blue simply dissolved in water for injection 

 of the ducts of glands, urinary canals, biliary plexuses, and also for 

 lymphatic canals. Ten grains of sulphate of iron, dissolved in 

 I ounce of water; 32 grains of red prussiate of potash in another 

 ounce of water, and both carefully combined make a good fluid. 

 If the canals to be filled are very fine, double the quantity of each 

 salt is to be added to each ounce of water. Glycerine may be 

 added if desirable. 



