246 ANNUAL OF SCIENTIFIC DISCOVERY. 



required to be sunk in this branch of trade, and above all to shorten the time 

 required to bleach the was, M. Cassgrand, of France, some years since, in- 

 vented a process which has been most successful, but has only recently come 

 before the public. 



This process consists in melting the wax by means of steam until it becomes 

 very liquid, and then passing it along with the steam through a kind of ser- 

 pentine worm, by which a large surface becomes exposed to the action of the 

 steam. After traversing the worm, it is received in a pan with a double bot- 

 tom, heated by steam, where water is added in order to wash it ; from this it 

 is elevated by a pump, kept hot by steam, into another pan similarly heated, 

 and where it is also treated with water, and is again passed through The ser- 

 pentine. This operation is repeated twice, thrice, or four times, according to 

 the quality of the wax. During the passage with the steam through the worm 

 it becomes denser, by absorbing, it is said, and deposits in the upper pan. It 

 is allowed to repose for about 4 or 5 minutes after each passage, and after 

 the last one, about 1 or 2 hours, according to quantity, in order to allow of 

 any impurities to subside. The wax is then granulated hi the ordinary way 

 by means of cold water, is allowed to dry during 3 or 4 days, and the ac- 

 tion of light and air does the rest, for which one person is sufficient. The 

 whole of the operations do not require more than a few days, are perfectly 

 certain, and attended with no danger. Independent of the advantage which 

 such an apparatus has for bleaching wax, it has also that of enabling its qual- 

 ities, according to relative whiteness, to be distinguished. For this purpose 

 it is only necessary to present the wax in masses to the end of the worm, and 

 in a second or two the vapor determines the relative color it will yield. This 

 process is also applicable to the purification of tallows and oils ; even fish-oil, 

 when passed through the apparatus and washed as described, is completely 

 deprived of its disagreeable smell ; and if it be set aside in a place where the 

 temperature only reaches from 59 to 68 Fahrenheit, a fresh deposit will 

 form, and the oil become perfectly clarified and nearly colorless. 



This process is worthy the attention of soap-boilers, as it is much more 

 effective than the present method of purifying oils, especially where sulphuric 

 acid is used. The only modification required for the purification of oil would 

 be to divide the oil as much as possible by means of a diaphragm of copper, 

 pierced with holes in the first steam-vessel, and thus expose the largest pos- 

 sible surface to the action of the steam in flowing through the pierced dia- 

 phragm into the worm. Dublin Journal, Industrial Progress. 



DISTILLATION OF- COAL IN HYDROGEN GAS. 



It is well known to chemists and others who. have experimented in the de- 

 structive distillation of coal, that at different degrees of temperature products 

 of very different character are produced gaseous, liquid, and solid. The gas- 

 eous products consist of marsh gas, olefiant gas, carbureted hydrogen, and 

 carbonic acid. The liquids consist of bodies closely analogous to petroleum, 

 and the solids are coke and mineral pitch. The relative proportions of the 

 above products vary with the temperature of the retort ; the lower the tern- 



