600 MEDICINES. 



Physic is said to " set " when the evacuations cease to be watery, 

 and the dung assumes its usual form. 



Aloin 



is the active purgative principle of aloes, to which it should always 

 be used in preference, if a little extra expense can be afforded. 

 Probably the best kind is obtained from Barbadoes aloes, and is 

 called Barbaloin. It acts quicker (in about fourteen hours), and is 

 safer, in that it causes less depression, loss of appetite, nausea, 

 griping, and straining than aloes ; and is quite as effective. Besides, 

 it is devoid of the sickening smell and taste of aloes, and it is 

 not liable, like aloes, to set up excessive staling (diuresis), instead 

 of purging. It is about 2J times as active. Hence, 2 drachms of 

 aloin will purge a horse quite as well as 5 drachms of aloes. 



Alum 



is soluble in 18 parts of cold water. Its astringent effect is owing to 

 its power of coagulating albumin. Dissolved in water, or used in 

 the form of powdered burnt alum, it is a fairly good application 

 for sores or wounds. Burnt alum can be prepared by heating to 

 dryness, alum which is placed over a fire on a metal or earthen 

 plate. It can be procured at any chemist's shop. 



Ammonia 



is used in making stimulating applications; and, internally, as a 

 general stimulant. Liquid ammonia is mad© by adding two parts 

 of water to one part of strong liquid ammonia (S. G. -891). 



Sowp Liniment. 



Soap ... ... ... ... .. 2 oz. 



Strong liquid ammonia ... ... ... 1 ,, 



Water ... ... ... ... ... 4 pints. 



Boil the water and dissolve the soap in it. When cold, add the 

 ammonia. 



Stimulating Liniment. 

 Soap liniment ... ... ... ... i pint. 



Strong liquid ammonia ... ... ... 1 to 2 drachms. 



Ammonia, Carbonate of, 

 is a valuable stimulant. Dose, 2 to 4 drachms. If given in a 

 drench it should be largely diluted. 



Ammonium Chloride (^Sal-ammoniac). 

 See p. 541. 



