614 MEDICINES. 



Calomel {^Mercury, Chloride of). 

 See p. 632. 



Camphor 



is, externally, a useful antiseptic, and allays irritation of the skin. 

 As it is an antispasmodic, \ oz. dissolved in a pint of oil is a 

 good oolic drench. See pp. 69 and 615. 



Cannabis Indica. 



See " Indian Hemp " (p. 623). 



Cantharides {Fly blister). 

 Cantharides ointment (1 to 7 of lard) acts well as a blister. 



Tincture uf Cantharides. 



The tincture of cantharides used in human practice is, as a rule, 

 too weak for horses, for the blistering of which a specially strong 

 tincture of cantharides is made by veterinary chemists. A some- 

 what similar tincture may be prepared by putting in a bottle 

 1 oz. of powdered cantharides and 1 pint of spirits of wine ; 

 keeping it corked for about a week, with occasional shaking up ; 

 and then filtering it. 



Carbolic Acid 



is a powerful antiseptic (pp. 67 and 69), and when externally 

 applied, is a soother of pain. 



There are three forms of carbolic acid in general use, viz., the 

 pure or glacial form, Calvert's disinfecting, and crude carbolic acid. 

 The first, except perhaps for internal use, is too expensive for 

 employment in ordinary veterinary practice. When given inter- 

 nally, a third more of Calvert's preparation should be employed 

 than would be necessary with the purer form. Crude carbolic acid, 

 which is very cheap, may be used as a disinfectant. The impurities 

 contained in impure carbolic acid have a very irritating effect, 

 eixternally as well as internally. 



When carbolic acid is dissolved in water, its effect is stronger 

 than when dissolved in oil or glycerine. 



It (especially the impure kind) is sparingly soluble in water, but 

 combines with glycerine in the proportion of 1 to 4, and may then 

 be diluted by water to any required strength. 



