602 MEDICINES. 



Calomel. 



See p. 621. 



Camphor 



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

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

 good colic drench. See pp. 69 and 603. 



Cannabis Indica. 



See " Indian Hemp." 



Cantharides. 



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

 Tincture of 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. 

 We may prepare a somewhat similar tincture 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 expen- 

 sive for employment in ordinary veterinary practice. When 

 given internally, 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, externally as well as internally. 



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

 than when dissolved in oil or glycerine. Koch has proved that 

 " carbolic oil," made by mixing 1 part of the acid with 10 parts 

 of olive oil, will not kill germs. 



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 



