March 1, 1892.] 



KNOWLEDGE 



57 



earthenware pots inverted above them, the joints being 

 made tight by hemp and clay. The water in the trough 

 is heated to boiling, and the steam passing through the 

 holes saturates the chips, causing the Camphor to sublime 

 and condense in crystals in the inverted pots above. 

 The Camphor thus obtained is sent into the interior of 

 the island, to Tasmin, the principal port, packed in baskets 

 covered with cloths and large leaves. On arrival, it is re- 

 packed in tubs or lead-lined cases for export by Chinese 

 vessels to Hong Kong, Shanghai or Canton, the loss by 

 evaporation while in transit from the place of its production 

 being very large. A yellow oil exudes from the packages 

 of this crude Camphor, locally known as " Oil of Camphor," 

 and is used medicinally. The Formosa Camphor, which 

 sometimes goes by the name of " Chinese Camphor," 

 occasionally arrives in India in a semi-fluid state, owing to 

 the addition of water before shipment. 



The Japan Camphor used to be extracted, according to 

 Kiimpfer (the authority above referred to), by boiling the 

 wood with water in an iron kettle, and condensing the 

 vapour in an earthenware dome, closed at the top with 

 rice-straw-. The modern practice is to distil the wood with 

 water in an iron retort fitted with a wooden dome, fi-om 

 which the vapours are led through a bamboo tube to the 

 cooling apparatus. This consists of a wooden box, 

 contaLnLng seven transverse compartments, and is enclosed 

 in a second bos through which water is allowed to flow ; the 

 vapours are conducted through all the compartments 

 in succession by means of holes placed alternately at 

 either end of the dividing walls. The Japan Camphor 

 arrives dry ; it is lighter in colour, and somewhat 

 jiinkish. It arrives in double tubs (one within the other) 

 without metal lining ; hence it is sometimes called 

 " tub-Camphor." 



The European process of refining Camphor was long kept 

 a secret, and towards the end of the seventeenth century the 

 entire Camphor of Europe had to be sent to Holland to be 

 sublimed. A monopoly was also held for some time in 

 Venice, but at the present day Camphor refining is largely 

 accomplished in England, Holland, Hamburg, Paris, New 

 York and Philadelphia. Before describing the correct 

 European method, it may be well to describe the fi-audulent 

 method adopted in India, the artful peculiarity of which is 

 to get as much interstitial water as possible into the 

 Camphor cake. The vessel used is a tinned cylindrical 

 copper drum, one end of which is removable ; into this is 

 put 14 parts of crude Camphor, and 2^ parts of water ; the 

 cover is then luted with clay, and the drum being placed 

 upon a small furnace made of clay is also luted to the top 

 of the furnace. In Bombay, four of such furnaces are 

 built together, so that the tops form a square platform. 

 The sublimation is completed in about three hours ; during 

 the process, the drums are constantly irrigated wuth cold 

 water. Camphor sublimed in this way is not stored, but 

 distributed at once to the store-keepers before it has had 

 time to lose weight by drying. It is sold at the same price 

 as the crude article, the refiner's profit being derived from 

 the introduction of water. The same practice seems to be 

 followed at Delhi, and at a few other cities in India. 



In Europe, it is usually refined by mixing it with lime, 

 charcoal, or iron filings, and subliming the mixture in 

 large glass vessels ; cakes weighing eight to twelve pounds 

 being thus obtained. 



The process adopted in Philadelphia is densed in such 

 a way as to obtain the sublimate in the form of a finely 

 powdered snowy mass, to accomplish which, about one- 

 tenth per cent, of water is added to the crude material. The 

 apparatus consists of a flat iron chamber, capable of holding 

 about 200 lbs., connected by means of an iron tube with a 



condensing chamber eight feet long, four feet wide, and 

 four feet high. This chamber is constructed of enamelled 

 briciis set in Portland cement, forming an arched roof and 

 floor of the same material. After an operation the apparatus 

 is allowed to remain undisturbed over night, to become 

 sufficiently cool. On removal of the sublimate, it is 

 compressed into moulds by hydi-aulic pressure of 

 2500 lbs. to the square inch, and the finished product 

 obtained in small cakes, highly compressed, and weighing 

 one ounce. 



Camphor forms a tough crystalline mass of characteristic 

 taste and odour, and can only be powdered when it is 

 moistened with alcohol or some other solvent. It dissolves 

 in 1300 parts of water at 20" C, and at 12° C. in 0-8 parts 

 of alcohol of sp. gr. 0-80G. It is readily soluble in ether, 

 acetone, chloroforrn, benzine, and other hydro-carbons ; 

 also in glacial acetic acid and in carbon disulphide. It 

 melts at 175° C, and boils at 204° C, but volatizes very 

 rapidly at the ordinary temperature and sublimes, when 

 kept in close vessels, in lustrous hexagonal crystals which 

 frequently form splendid stars. 



Camphor oil is used for mixing with fine lac varnishes, 

 rendering them less liable to crack. It is a powerful 

 antiseptic and disinfectant, and covers the smell of mineral 

 oils. 



,THE FACE OF THE SKY FOR MARCH. 



By Herbert Sadler, F.E.A.S. 



SUN-SPOTS are rapidly increasing in number and size, 

 a group being distinctly Ndsible to the naked eye at 

 the time of writing these lines. The following are 

 conveniently observable minima of some Algol-type 

 variables {<■/. " Face of the Sky," for February). 

 Algol. — March 10th, nine minutes after midnight ; March 

 13th, 8h. 58m. p.m. S Caucri. — March 16th, llh. 46m. 

 P.M. The student will, of course, keep a watch on Nova 

 AurigfE, at present about the fifth magnitude, the place of 

 which for 1892 is 5h. 25m. 3s.-|-30° 21'. Its spectrum 

 seems to resemble in some particulars those shown by 

 Novffi 1866 and 1876. 



Mercury is in superior conjunction with the Sun on the 

 6th, and after that he rapidly improves in position, setting 

 on the 16th at 7h. Im. p.m., 56m. after the Sun, with an 

 apparent diameter of oh", and a northern declination of 

 2^ 15', ja^a^ths of the disc being illuminated. On the 21st 

 he sets at 7h. 38m. p.m., or Ih. 24m. after the Sun, with 

 an apparent diameter of 6", and a northern declination of 

 6= 53', i^Vytlis of the disc being illuminated. On the 26th 

 he sets at 8h. 9m. p.m., or Ih. 47m. after sunset, with an 

 apparent diameter of 6i", and a northern declination of 

 10° 56', TTjLths of the disc being illuminated. On the 31st, 

 when he is at his greatest eastern elongation (18° 54'), he 

 sets at 8h. 28m. p.m., or just upon two hours after the Sun, 

 with an apparent diameter of 7^", and a northern declina- 

 tion of 13° 58'. The student may be reminded that 

 Mercm-y is at his greatest brilliancy about ten days or a 

 fortnight before his greatest eastern elongation, notwith- 

 standing that at his greatest eastern elongation he sets 

 considerably later in the evening. While visible, Mercury 

 describes a direct path through Pisces to the borders of 

 Aries. 



Venus is now becoming a very bright object in the 

 evening sky. She sets on the 1st at 9h. 18m. p.m., with a 

 northern declination of 7° 52', and an apparent diameter 

 of lli", I'tfotlis of the disc being illuminated. On the 21st 

 she sets at lOh. 18m. p.m., with a northern declination of 

 17° 8', and an apparent diameter of 16J", jfyoths of the 



