MERCURY PILL 291 



MERCURY WITH CHALK. Hydrargyrum cum Greta. Grey 

 Powder. 



This mixture is made by triturating together one part 

 mercury with two of prepared chalk until globules disappear, 

 and a uniform grey colour is acquired. Grey powder should 

 be free from grittiness, and insoluble in water ; but its chalk 

 dissolves in hydrochloric acid, leaving the mercury in a 

 finely-divided state. 



Grey powder is antacid, laxative, and alterative. It is 

 given with good effect to young calves and foals suffering 

 from indigestion and diarrhoea, in doses of five to fifteen 

 grains, repeated once or twice a day, conveniently placed on 

 the patient's tongue, or administered with a drachm of 

 ginger, in spirit and water, milk, or gruel. To allay gastric 

 irritation, caused by constipation and putrefactive changes 

 in the intestine, and as an alterative for dogs, one to three 

 grains are prescribed two or three times daily ; but such 

 treatment is only advisable for robust patients. 



MERCURY OR BLUE PILL. Pilula Hydrargyri. 



This pill, so much used in human medicine, is seldom 

 employed in veterinary practice. It consists of two parts 

 mercury, three of confection of roses, and one of liquorice 

 root. Mayhew recommended, as a cathartic for a medium- 

 sized dog, five grains blue pill, six grains powdered colchicum, 

 and ten grains colocynth extract. Five grains blue pill and 

 eight grains compound extract of colocynth, flavoured with 

 a few drops of oil of peppermint or of cloves, make a con- 

 venient laxative for a large dog, or two or three doses for a 

 small one. The activity of mercury pill in part results from 

 its containing a small proportion of oxide, which is readily 

 dissolved by the acid gastric juice. 



MERCUROUS OXIDE. Hydrargyri Suboxidum. Hg 2 0. 



Mercurous, black, grey, or lower oxide is prepared by 

 decomposing calomel (Hg 2 Cl 2 ) with caustic potash solution, 

 and washing with water. It is a heavy black powder, devoid 

 of taste or odour, insoluble in water and alkalies, but soluble 



