AND PHARMACOPCEIA. 455 



dose should be given. Mr. Bracey Clark's method of mixino- 

 aloes for physic is most easy : and if ginger and some essential 

 oil are not necessaiy, which he says is the case, his method may 

 be the best : especially if the physic is wanted to act only on the 

 large bowels. Soap as well as soda and potash promotes the so- 

 lution of aloes, and causes it to act on the small bowels, and 

 probably sometimes on the stomach also, as appears from the 

 sickness it sometimes induces when thus mixed. This quickness 

 of solution, however, is certainly desirable when there are worms 

 in the small bowels, and in cases Avhere a speedy operation is 

 desirable. The method INIr. Clark recommends, is to put with 

 any quantity of aloes, broken into small pieces, one fifth part by 

 Aveight of treacle, and keep the vessel containing it in boiling 

 water, until the aloes are melted and incorporated with treacle. 

 It is necessary to stir the mixture well after it has been in the 

 boiling water a short time, and when perfectly melted and in- 

 corporated, Mr. Clark directs it to be poured into paper moulds. 

 I have found, however, that by pouring the mixture upon a 

 marble slab or plate, previously greased with butter, it soon ac- 

 quires a proper consistence to be formed into balls. 



[The following formula is recommended by Mr. Morton : — 



Aloes in small pieces 8 parts. 



Olive oil 1 part. 



Treacle 3 j^arts. 



The aloes and oil to be melted together in a water bath, and 

 when removed from the fire the treacle is to be added, and the 

 whole stirred together. When Cape aloes are used Mr. Morton 

 withholds half the oil and substitutes water. I have been in the 

 habit of making the cathartic mass in a similar manner, but sub- 

 stituting one part of powdered ginger instead of an equal portion 

 of oil and treacle, which I found to form a mass of better con- 

 sistence and less likely to run. I have also added a few drachms 

 of powdered tartaric acid, the effect of which has been to assist 

 the union of the mass, and prevent it adhering to the fingers. 

 The Barbadoes extract is certainly more certain in its effects 

 than the Cape, but the latter may be rendered equally so by the 

 addition of croton oil, nine drops of which added to six drachms 

 of Cape aloes, will render it of the same strength as an equal 

 quantity of Barbadoes aloes. — Ed.] 



Under the head Drenches will be found directions for 

 making liquid purgatives. 



CAUSTICS are substances that burn or destroy parts to 

 which they are applied. The most powerful is the red-hot iron, 

 or actual cautery, which is often employed in veterinary practice 

 to remove spavins, &c. (See Firing.) Many of the other 

 caustics are possessed of great strength, and speedily destroy 



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