PICRIC ACID 339 



ACTION, USES, AND DOSES. The strong acid is very 

 corrosive and irritant, but it is not used as a caustic. Medi- 

 cinal doses are said to exert special tonic and stimulant 

 actions on the liver and intestinal glands, and are used 

 in hepatic torpidity, catarrhal jaundice, rickets, and occa- 

 sionally in equine influenza. The presence of free chlorine 

 may help to explain this action on the liver. It is prescribed 

 with the same precautions as to dilution as nitric acid. 

 Doses, horses and cattle, 3J- to 3ij- ; sheep and pigs, u\x. 

 to 3J- ; dogs, H\ij. to ll\xx., in drench. 



PICRIC ACID 



Acidum picricum or trinitrophenic acid, prepared by the 

 action of fuming nitric acid on phenol, occurs in yellow, 

 shining, odourless crystals, having a very bitter taste ; 

 slightly soluble in water ; very soluble in alcohol, ether, and 

 chloroform. Heated slowly with free access of air picric 

 acid burns ; heated rapidly it explodes. It precipitates 

 albumin in acid solution, stains the skin, and hair, or wool 

 yellow, and with bases forms salts, of which the most im- 

 portant in veterinary practice is potassium picrate. Picric 

 acid is a powerful antiseptic and vermicide, and a very active 

 desiccant. Applied externally in suitable cases it promotes 

 the formation of epidermis and hastens the cicatrisation of 

 cutaneous wounds, and in solution or ointment it has been 

 used in the treatment of eczema, pruritus, and burns. It 

 is seldom prescribed as an anthelmintic as it is liable to 

 produce fatal gastro-enteritis. The toxic dose for the dog 

 is ten grains (Kaufmann). 



Picrate of potash, which is much less irritant and toxic 

 than the acid, has been employed as a vermicide in sheep 

 and pigs. 



DOSES (picric acid). Lambs, grs. jss to grs. iijss ; (picrate 

 of potash), lambs, grs. vii. to grs. xv. per day ; young pigs, 

 grs. iijss to grs. viii., per day, in gruel, mucilage, or in bolus. 



CONCENTRATED PHOSPHORIC ACID 



Acidum phosphoricum concentratum, a liquid containing 

 66- 3 per cent, of hydrogen orthophosphate H 3 P0 4 , with 



