AND PHARMACOPCEIA. 451 



sometimes given with cordials. According to Dr. Paris, cinchona 

 cascarilla, and other medicines which contain tannin and the 

 gallic acid, or, in other words, which strike a black colour with 

 iron, are decomposed by the sulphates. According to this doc- 

 trine, cascarilla would be what he terms an incomjiatible ingre- 

 dient with the sulphates of iron, of copper, and of zinc. The 

 dose of cascarilla is one, two, or three drachms in powder. 



CASSIA BARK. — Lcmri Cassioi Cortex. The tree from 

 which this bark is obtained is a native of Malabar, Ceylon, 

 Sumatra, and Java, and has by some been accounted a variety 

 of the cinnarnon-tree, the odour of which it in some degree re- 

 sembles. It is sent to this country in sticks or quills ; is of the 

 colour of cinnamon, and, if broken, appeal's to consist of two dis- 

 tinct rinds or barks, the inner of which is darker than the outer, 

 and possesses the flavour of cinnamon, though a little more pun- 

 gent, whilst the outer has scarcely any taste whatever. There 

 are some fine pieces of cassia which so nearly resemble cinnamon, 

 as not to be easily distinguished from it, and are frequently sold 

 for it in the shops. For every veterinary purpose cassia is equal 

 to cinnamon, provided it is well chosen : such parts should be 

 selected as have a pleasant, sweetish taste, succeeded by one ex- 

 tremely hot and pungent : this is generally found in the thinner 

 pieces, which are curled up like cinnamon. 



Cassia is a strong aromatic stimulant, and an efficacious in- 

 gredient in cordial preparations. The dose is from one to two 

 drachms. An essential oil is obtained from cassia, which bears 

 a high price, but is so excessively powerful, that two drops on a 

 lump of sugar will Impart a strong taste to half a pint of water. 



CASSIA BUDS. These nearly resemble cassia in their 

 taste and medical qualities, and may be used for the same 

 purposes. 



CASTOK OIL. — Oleum Ricini. Castor oil is obtained by 

 boiling, or by expression from the seeds of the ricinus or palma 

 Christi, a plant found in the East and West Indies, in Greece, 

 South America, Africa, and on the Rock of Gibraltar. The 

 former method was generally used till lately, and was performed 

 by tying up the seeds in a bag, (having previously taken off the 

 bark and bruised them,) and suspending the bag in boiling water 

 till all the oil was extracted and rose to the surface, when it was 

 skimmed off; but it is now more generally obtained by pressure 

 like that of almonds or olives. The castor or ricinus seeds are 

 a strong pvu'gative. The best castor oil is made in England 

 from cold blanched seeds with the eye taken out. It is said that 

 the dark-coloured castor oil, brought from the West Indies, is 

 bleached or rendered colourless by some process in this country, 

 and sold as cold-drawn castor oil. Castor oil is an excellent 

 purgative, as it opens the bowels without producing griping or 



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