MODERN METHODS OF EXAMINATION. 71 



most usual. Lieberkuhn used tallow, varnish, and tur- 

 pentine, colored with cinnabar ; and Hyrtl, whose prepa- 

 rations have been much admired, follows a similar plan. 

 He evaporates pure copal or mastic varnish to the consis- 

 tence of syrup, and grinds one-eighth as much cinnabar 

 and a little wax with it on a slab. For fine injections this 

 is diluted with ether. 



For a bright red, the cinnabar may be mixed with a 

 little carmine. 



For a yellow color, the chromate of lead, prepared by 

 mixing solutions of acetate of lead (36 parts to 2 ounces 

 of water), and red chromate of potash (15 parts). 



White may be made with zinc-white or carbonate of 

 lead ij ounces of acetate of lead in 16 ounces of water, 

 mixed with 3J ounces carbonate of soda in 16 ounces. 



For gelatinous injections the coloring matter is com- 

 bined with jelly, prepared by soaking fine gelatin in cold 

 water for several hours, then dissolving in a water-bath 

 and filtering through flannel. 



By injecting gelatinous fluid solutions of various salts, 

 the coloring matter may be left in the vessels by double 

 decomposition. 



A red precipitate, with iodide of potassium and bichlo- 

 ride of mercury. 



A blue, by ferrocyanide of potassium and peroxide of 

 iron, etc. 



Dr. Goadby's formula for a yellow color is : 



Saturated solution of bichromate of potassium, . 8 ounces. 



Water, 8 " 



Gelatin, 2 " 



Saturated solution of acetate of lead, . . .8 ounces. 



Water, 8 " 



Gelatin, 2 " 



For gelatinous injections, both the fluid and the subject 

 should be as warm as may consist with convenience. 

 Camphor also should be added to prevent mould. 



