748 CASTOR OIL 



appearance. If cashed with ammonia, on the filter, while still moist, it dissolves, and 

 a purple liquid passes, which rivals the hypermanganato of potash in beauty. . . . 

 It may also be formed by fusing together 2 parts of gold, 3J parts of tin, and 15 parts 

 of silver, under borax, to prevent the oxidation of tho tin, and treating the alloy with 

 nitric acid, to dissolve out the silver ; a purple residue is left, containing the tin and gold 

 that were employed. 1 



' Berzelius proposed the theory that the powder of Cassius may contain the true prot- 

 oxide of gold combined with sesquioxide of tin, AuOSn 2 8 , a kind of combination 

 containing an association of three atoms of metal, which is exemplified in black oxide 

 of iron, spinele, Franklinite, and other minerals. ... A glance at its formula shows 

 how readily the powder of Cassius, as thus represented, may pass into gold and binoxide 

 of tin, AuOSn !i O' 1 '=Au + 2SnOV Graham and Watts. 



CASTII.E SOAP, or Spanish Soap, is prepared with olive oil and a solution 

 of caustic soda. There are two varieties, the white and the marbled. Tho marbled 

 appearance is produced in the soap, by adding, as soon as it is made and separated 

 from the spent ley, a fresh quantity of ley, and immediately a solution of the proto- 

 sulphate of iron. A precipitate of oxide of iron is at once formed, and this gives 

 the dark coloured streaks to the soap. By exposure to the air these streaks become 

 red, in consequence of the conversion of the black oxide of iron into the red or sesqui- 

 oxide. See SOAP. 



CAST-IRON. See IRON. 



CAST-IRON SCOURING. Cast-iron surfaces are said to be easily scoured by 

 adding a little of any kind of organic matter, such as glycerine, stearine, naphthaline, 

 or creosote to dilute sulphuric acid ; zinc and brass yield to the same method, with 

 great economy of labour, time, and material. 



CASTOR. A mineral occurring in Elba, associated with another species called 

 Pollux. Castor is a silicate of alumina and lithia, closely related to, if not identical 

 with, petalite. 



CASTOR. The Beaver. See FTJHS. 



CASTOR, or CASTOREU1VI. This name is given to a secretion of the Beaver 

 (Castor fiber), contained in pear-shaped cellular organic sacs, placed near the genital 

 organs of both the male and female animals. It is a substance analogous to civet and 

 musk, of a consistence similar to that of thick honey. It has a bitter acrid taste ; a 

 powerful penetrating, fcetid, and very volatile smell. 



Several chemists, and in particular Bouillon, Lagrange, Laugier, and Hildebrandt 

 have examined castor, and found it to be composed of a resin, a fatty substance, a 

 volatile oil, an extractive matter, benzoic acid, and some salts. 



The mode of preparing it is very simple. The sacs are cut off from the castors 

 when they are killed, and are dried to prevent the skin being affected by the weather. 

 In this state the interior substance is solid, of a dark colour, and a faint smell ; it 

 softens with heat, and becomes brittle by cold. Its fracture betrays fragments of mem- 

 branes, indicating its organic structure. When chewed it adheres to the teeth some- 

 what like wax ; it has a bitter, slightly acrid and nauseous taste. 



The castor bags, as imported, are often joined in pairs by a kind of ligature. 

 Sometimes the substance which constitutes their value is sophisticated ; a portion of 

 the castor being extracted, and replaced by lead, clay, gums, or some other foreign 

 matters. This fraud may be easily detected, even when it exists in a small degree, 

 by the absence of the membranous partitions in the interior of the bags, as well as 

 by the altered smell and taste. 



Castor is used to a small extent in medicine and in perfumery manufacture, the 

 latter particularly when ambergris is scarce. 



In English commerce, two varieties of American castor are made : one called the 

 Hudson's Bay and the other the Canadian though both are imported by the Hud- 

 son's Bay Company. 



CASTORINE. A substance existing in castor. It is obtained by treating castor 

 with hot alcohol, and filtering through a Platamour's ebullition funnel. On cooling, 

 the alcohol deposits crystals of a fatty substance. Tho castorine is retained in 

 the mother-liquor, and is procured by evaporation on the water-bath to a small 

 bulk, and then setting aside to allow crystals to form. Castorine crystallises in 

 needles possessing a slight odour of castoreum. C.G.W. 



CASTOR oil.. The expressed oil of the seeds of the Palma Christi or Eicinus 

 communis, a native of the West Indies and South America; but which has been 

 cultivated in France, Italy, and Spain. 



In England tho castor oil is expressed from the seeds by means of powerful hydrau- 

 lic presses fixed in rooms artificially heated. It is purified by repose, decantation, 

 and filtration, being bleached in pale-coloured Winchester quart bottles, which are 

 exposed to light on the tops of houses. 



