30 
three-fourths of a gallon of a liquid having a specific gravity of 
700 to 715 (water being taken as 1000) is obtained; and this, 
on further treatment in rectification, is divided into gasoline and 
light naphtha. The non-luminous gases are then passed under 
the retorts, and consumed in the furnaces as fuel. The sub- 
stances thus produced by the destructive distillation of shale 
are afterwards submitted to fractional distillation, and to other 
chemical treatment. To describe these processes would occupy 
more time than I have at command; and I shall, therefore, 
merely summarize the products, giving their special features of 
commercial or scientific interest. 
From figures given by Mr. R. H. Brunton, M. Inst. C.K. 
(to whom the writer is indebted for much information on this 
subject), it appears that, in the year 1881, the total shale used 
in Scotland was 1,036,000 tons, yielding— 
Gasolingye.t dipacn ce 85,000 gals., being 0°25 per cent. 
Naphthalene craters 1,955,000, 3 Oke 3 
Burning oils ........ 11,900,000 _,, » 35°00 A 
Lubricating oil ...... 4,760,000 __,, », 14:00 fe 
Girecnwoil iain. oe 85,000, 532 0225; 55 
Solid Paraffin........ 3,060,000 __., » 9:00 * 
Loss on fractionation ; ; 
of crude oil ...... } 12,155,000 ,, » 85°75 a 
UMN econ aco 34,000,000 gals. 100-00 
Gasoline, the most volatile of the products, can be made of 
gravities from 640 to 680; but it is only produced in small quanti- 
ties, as already explained. It is used for adding luminosity to 
air or other gases, for use where coal gas is not readily obtainable. 
Naphtha has a gravity ranging from 700 to 760. Its abstrac- 
tion from the burning oils renders them less inflammable. Some 
quantity is disposed of as a solvent for caoutchouc and gutta- 
percha, and as benzoline for sponge lamps; but a large proportion 
of the production is consumed in the ordinary open-air naphtha 
lamps. 
Binion oils are usually separated into four qualities, de- 
pending on their specific gravities and flashing points, as well as 
on their colours and odours. 
Lubricating oils are of gravities ranging from 875 to 890. 
They have the great defects, as lubricants, of being deficient in 
body or viscosity. The viscosity of the best qualities of paraffin 
lubricating oils does not exceed two-fifths that of rape ; while 
many of the heavier oils are as low as one-fourth. 
Green oil is obtained from the tarry refuse. It is rich in 
carbolic acid; and is not yet much used. 
Paraffin wax, as made, is separated iuto portions of varied 
fusibility. That of low melting point is used in the manufacture 
of match-tips; while that of higher melting point is chiefly used 
