512 PARAFFIN 



refining with much advantage, the cost of working being very much less, and the yield of 

 white paraffin notably larger than formerly. As no spirits are used, a loss of about 1 cwt. 

 of them'for every ton of finished paraffin is avoided. As redistillation of the expressed 

 oils also ceases, no loss occurs in this way of solid paraffin in solution. Much 

 more safety also accompanies the operations of the i'actory. The rationale of the 

 process consists in subjecting the paraffin, after being previously washed with sul- 

 phuric acid and soda, to hot pressure and filtration at the same time. The following 

 details of two experiments on the commercial scale show the working of the pro- 

 cess: 



In the first experiment, good average scale was first boiled, and blocked into a cake, 

 which, on being cold-pressed, yielded lubri eating-oil and pressed cake ; which, after 

 being again boiled and blocked, was subjected to the new method, giving a hard 

 paraffin, which, after treatment with acid, alkali, and ivory-black, yielded finished 

 paraffin equal to that made with the ordinary process, and having a melting-point 

 of 129. 



There was taken of the scale 200 cwts. 1 qr. 26 Ibs., which gave : 



cwts. qrs. Ibs. per cent. 



Finished paraffin . 131 1 27 = 65-68 



Soft paraffin, &c., of the value of iths of original 



scale ' . . 35 12 17'51 



Dark rough oil . . . . . . . 17 2 5 8'75 



91-84 

 Loss, including paraffin left in ivory-black . .16110 8-16 loss. 



200 1 26 100-00 



In the second experiment, scale of a low melting-point was treated as above ; only 

 submitted twice to the special process. A paraffin with a melting-point at 130 re- 

 sulted : 



Of the scale taken 69 cwts. 26 Ibs. there remained 



cwts. qrs. Ibs. per cent. 



White paraffin 39 3 27 = 57'83 



Soft paraffin, &c., valued at fths of original scale . 18 1 27 26-74 

 Hough dark oil . . . . . .630 976 



94-33 



69 26 5-67 loss. 



100-000 



This process must be of immense service in extracting solid paraffin for its own sake 

 from minerals in places where mineral spirits are not a drug, as in our own mineral- 

 oil factories. 



Paraffin is mixed with 5 to 15 per cent, of stearine when moulded into candles ; 

 and to do this thoroughly well the moulds must be kept for at least an hour in a bath 

 of hot water, at a temperature of about 190 Fahr. The mixed stearic acid facilitates 

 the colouring of paraffin candles. 



The following particulars of the paraffin trade in Scotland, derived from an 

 authentic source, cannot be without interest : 



It is difficult to obtain statistics of the yield of burning-oil, lubricating oil, and the 

 other products derived from shale in the process of oil-making. Naturally enough, 

 one manufacturer does not care to let another know the particulars of his production. 

 Hence, at best, nothing more than an estimate can be arrived at ; but this coming 

 from a source which may be relied upon, will give a tolerably fair idea of the extent 

 of this important trade. It is estimated that not less than 800,000 tons of shale are 

 annually put into the retorts at the various Scotch oil works. The probable yield of 

 crude oil from this source is reckoned at 25,000,000 gallons. To obtain this result, 

 and also for the distillation of the crude, a great amount of fuel say 500,000 tons 

 must be used. The principal product from tho crude is, of course, burning-oil, of 

 which from 300,000 to 350,000 barrels may be taken as the annual yield. Some 

 of this is sent to the Continent, but the bulk is consumed in this country. Then we 

 have of lubricating-oil, the demand for which appears t be increasing every day, say 

 9,800 tons. Also paraffin wax, of which the bulk is made into beautiful semi-trans- 

 parent candles, and the commonest of it is used in the manufacture of lucifer- matches, 

 say 5,800 tons. To these figures we may add some 2,300 tons of sulphate of 



