CAMPHORA. 51.=) 



The solubility of camphor in water is very small, 1300 parts dissolv- 

 ing about one ; but even this small quantity is partially separated on 

 addition of some alkaline or earthy salt, as sulphate of magnesium. 

 Alcohols, ethers, chloroform, carbon bisulphide, volatile and fixed oils 

 and liquid hydrocarbons, dissolve camphor abundantly. 



The sp. gr. of camphor at 0" C. and up to 6° is the same as that of 

 water ; yet at a somewhat higher temperature, camphor expands more 

 quickly, so that at 10° to 12° C. its sp. gr. is only 0"992. 



In concentrated solution or in a state of fusion, camphor turns the 

 plane of polarization strongly to the right. Officinal solution of camphor 

 (Spiritus Cainphoroi) is too weak, and does not deviate the ray of light 

 to a considerable amount.' Crystals of camphor are devoid of rotatory 

 power. 



The taste and odour of camphor are sui generis, or at least are com- 

 mon only to a group of nearly allied substances. Camphor is not 

 altered by exposure to air or light. It burns easily, affording a brilliant 

 smoky flame. 



Chemical Composition. — Camphor, C'"!!'*©, by treatment with 

 various reagents, yields a number of interesting products : thus when 

 repeatedl}' distilled with chloride of zinc or anhydrous phosphoric acid, 

 it is converted into Cymene or Cymol, C^'^H^*, a body contained in many 

 essential oils, or obtainable therefrom. 



Camphor, and also camphor oil, when subjected to powerful oxidizing 

 agents, absorbs oxygen, passing gradually into crystallized Cmnphoric 

 Acid, C^^Hi^O^ or C«Hi*(COOH)-', water and carbonic acid being at the 

 same time eliminated. Many essential oils, resins and gum-resins 

 likewise j'ield these acids when similarly treated. 



By means of less energetic oxidizers, camphor may be converted into 

 Oxy-Camphor, C^^H^^O-, still retaining its original odour and taste 

 (Wheeler, 1868). 



Commerce — Two kinds of crude camphor are known in the English 

 market, namely : 



1. Formosa or China Camphor, imported in chests lined with lead 

 or tinned iron, and weighing about 1 cwt. each ; it is of a light brown, 

 small in grain, and always wet, as the merchants cause water to be 

 poured into the cases before shipment, with a view, it is pretended, of 

 lessening the loss by evaporation. The exports of this camphor from 

 Tamsui in Formosa- were in peculs (one pecul = 1333 lb. avdp. = 

 60-479 kilogrammes) as follows : 



The shipments of camphor from Takow, the other open port of 

 Formosa, are of insignificant amount. Planks of camphor w^ood are 

 now exported in some quantity from Tamsui. 



2. Japan Camphor is lighter in colour and occasionally of a pinkish 



tint ; it is also in larger grains. It arrives in double tubs (one within 



the other) without metal lining, and hence is drier than the previous 



sort ; the tubs hold about 1 cwt. It fetches a somewhat higher price 



than the Formosa camphor. 



' Pharm. Journ. 18 April 1874. 830. ^ Betwns of Trade at the Treaty Ports in 



China for 1872, part. 2, p. 124. 



