FOSSIL HVDRO-CARBONS, THE SOURCE OP LIGHT, HEAT, COLOUR, ETC, 59 



often yield at the rate of fifty quarts of palm-wine in the twenty-four 

 hours. From this juice, after boiling, a brown sugar called jaggery is pre- 

 pared ; and when particular care is used, it is scarcely inferior to white. 

 The pith or farinaceous part of the trunk of old trees affords an article 

 nearly as good as the ordinary sago of commerce, which is used in Assam 

 as such. The natives make it into bread, and boil it into thick gruel. In 

 Ceylon there is a distinct caste of natives, the Jaggeraroos, who take the 

 name from all, male and female, being employed in the culture of the tree 

 itself, or in the manufacture of the coarse sugar (jaggery) procured from it. 



The split trunks of the kittool palm are used for rafters and window- 

 bars, and are found very hard and durable. The seeds are used by Maho- 

 medans as beads. 



FOSSIL HYDRO-CARBONS, THE SOURCE OF LIGHT, HEAT, 

 COLOUR, &c 



BY THOMAS D. ROCK. 



In the entire range of Technological subjects, there is none more 

 worthy of investigation than that I have selected for a few simple observa- 

 tions. Under whatever asjject I view my theme — whether it be the scien- 

 tific history of the hydro-carbons, or their abundant and daily-increasing 

 utility — I feel- lost in wonder and admiration ; and, impelled by a keen 

 desire to make myself and others better acquainted with materials which 

 play so important a part in the economy of daily life, I shall humbly 

 strive to rescue from the dark and mysterious avenues of science such 

 matters relating thereto, as shall be of special importance to readers of the 

 Technologist. 



Hydro-carbons are substances either solid, fluid, or gaseous, which con- 

 sist altogether, or primarily, of the two familiar elements whence the name 

 is derived, hydrogen and carbon. The latter body is ordinarily found in 

 three special conditions, — viz., as amorphous, in certain coals which consist 

 almost exclusively of pure carbon ; as foliated or scaly, in graphite (plum- 

 bago), which contains as much as 95 per cent, of the same substance ; and, 

 in its most beautiful or crystalline form, as the diamond, which is considered 

 to be pure carbon. Hydrogen is only known to man by its effects, and as 

 the principal element of water. It does not exist in nature as a separate 

 body, is with much difficulty disassociated from its intimate alliances, and 

 even then, from its gaseous form, has no visible appearance. 



From the earliest times man has appropriated the hydro-carbons for 

 the production of artificial light and heat ; although, possibly, without the 

 knowledge that such combinations really constitute the only available 

 source of these necessities of civilisation. The hydro-carbons which the 

 ancients used were, however, entirely supplied by existing vegetation. The 

 oil which they burnt in their lamps, and the wood with which they reple- 

 nished their ovens, were all of recent formation ; and such stores are still 

 available in new and primitive countries. Colonists of Australia or 



