THE HORSE. 



81 



and press the piston steadily until a sensible 

 resistance is felt. If much force be used, 

 rupture of a vessel may take place. After 

 a prudent force has been applied for some 

 time, the syringe may be withdrawn, pre- 

 viously securing the stop-cock. A steady 

 and uniform pressm-e on the piston will be 

 more likely to secure uniform injection than 

 force, or sudden jerks. Should the first in- 

 jection fail to fill the vessels, it must be 

 immediately followed by a second. When 

 injecting through a very small pipe, the in- 

 jector must be patient, and steadily con- 

 tinue the pressure on the piston. 



When using ivarm injections, the syringe 

 must be kept luarm by immersing it in hot 

 water, and the part to be injected must also 

 be kept at the same temperature, by the 

 same means. 



DIFFERENT KINDS OF INJEC- 

 TIONS. 



There are six kinds of injections now in 

 use, viz., the cold, coarse, and fine injection, 

 the minute, the mercurial, and, finally, the 

 plaster of Paris injection. The five first 

 are most employed ; the plaster of Paris is 

 objectionable because it is easily firactured. 



FORMULA FOR COARSE WARM INJECTIONS. 



Red. — Beeswax, sixteen ounces; white 

 resin, eight ounces ; turpentine varnish, sLx 

 ounces ; vermilion, three ounces. 



First liquify the wax, resin, and turpen- 

 tine varnish, in an earthen pot, over a slow 

 fire, or in a water bath ; then add the Ver- 

 million, previously reducing it to a fine 

 powder, so that the coloring ingredients 

 may be intimately and smoothly blended, 

 then add the same to the above ingredients, 

 and, when they have accrued due heat, the 

 injection is fit for immediate use. 



Yellow Injection. — Take beeswax, eight 

 ounces ; resin, four ounces ; turpentine var- 

 nish, three ounces ; yellow ochre, one ounce 

 and a quarter. 



While Injection. — Clarified beeswax, 

 eight ounces ; resin, four ounces ; turpen- 

 tine varnish, three ounces ; flake white, two 

 ounces and a quarter. 

 11 



Pale Blue Injection. — Take the preced- 

 ing ingredients, and add to them a small 

 portion of indigo. 



Black Injection. — Beeswax, resin, and 

 turpentine varnish in the above proportions ; 

 and add lamp-black ad libitum. 



The same rules are to be observed in pre- 

 paring all the injections. 



FORMULiE FOR FINE INJECTIONS. 



Red. — Brown and white spirit varnishes, 

 of each four ounces ; turpentine varnish, 

 one ounce ; vermilion one ounce. 



Yellow. — Brown and white spirit varnishes, 

 of each four ounces ; turpentine varnish, one 

 ounce ; king's yellow, one ounce and a half. 

 To make a white injection, add to the last 

 formula two ounces of flake-white instead 

 of king's yellow. 



Blue. — Brown and white spirit varnishes, 

 of each four ounces ; turpentine varnish, one 

 ounce ; Prussian blue, one ounce and a 

 half. This may be made black by adding 

 ivory black instead of Prussian blue. 



FORMULiE FOR MINUTE INJECTIONS. 



The liquifying principle in minute injec- 

 tions is " 5ice," which is made in the fol- 

 lowing mamier : 



Take fine transparent glue, one pound, 

 break it into pieces ; put it into an earthen 

 pot, and pour on it three pints of cold water ; 

 let it stand twenty-four hours, stirring it 

 occasionally with a stick ; then set it over a 

 slow fire until it is perfectly dissolved ; 

 skim off all the scum from the surface, and 

 strain the remainder through flannel ; it 

 will then be fit for the coloring ingredients. 



Minute Red Injection. — Size, one pint ; 

 vermilion, three ounces and a half. 



Yellow. — Size, one pint ; king's yellow, 

 two ounces and a half. 



White. — Size, half a pint ; flake white, 

 one ounce and three quarters. 



Blue. — Size, half a pint ; fine blue smalt, 

 six ounces. 



PLASTER INJECTION. 



Before mixing the plaster of Paris, the 

 pipes must be secured to the mouths of 



