1918] on The Romance of Petroleum 845 



up the ozokerite, and in lowering and raising the miners. The 

 descent was made by pi icing one f(;ot in the bucket and I olding on 

 to tlie rope, the other being used in fending the bucket off the sides 

 of tlie shaft. Owinu' to the sul)sidence and lateral movement of the 

 ground, due to the removal of the ozokerite, the shafts did not long 

 remain vertical, and the descent was not a pleasant experience. The 

 miner wore a safety-belt, to which a rope was attached. Much 

 inflammable gas was met with in the galleries, and safety-lamps were 

 necessarily used. Ventilation was unsatisfactorily effected by means 

 of a fan-i)lower. Within easy reach of the miner was a cord 

 attached to a bell at the mouth of the shaft, by means of which he 

 could summon assistance ; but notwithstanding the provision of the 

 bell and safety-belt deaths by suffocation were not uncommon. The 

 first effect of the inhalation of the gas produced a kind of intoxica- 

 tion, which some of the miners appeared to find enjoyable. It is 

 not surprising that work of this character, often conducted with 

 insufficient capital, inadequate appliances, and imperfect organisa- 

 tion, should have been attended with much unnecessary loss of life, 

 especially when tlie somewhat reckless character of those engaged in 

 it is taken into account. It was stated in 1871 that, among the 

 2000 underground workers then employed there were usually from 

 200 to 300 accidents yearly, nearly all of which were fatal, and that 

 in some years the number of deaths was as great as 1000. The 

 ozokerite candles which many of us can remember were n-ade from 

 ceresin, a product obtained hy subjecting the ozokerite to destructive 

 distillation in a current of superheated steam. These candles were 

 specially suited for use in tropical countries, owing to the high 

 melting-point of the material. Purified ozokerite has also been 

 largely employed as a substitute f^r or adulterant of beeswax, which 

 it closely resembles in physical properties, especially in the manu- 

 facture of church candles, in cases where the employment of paraffin- 

 wax is prohibited by ecclesiastical law. 



Crude petroleum varies greatly in character, as is shown by the 

 representative collection of specimens from various parts of the world 

 which is on the lecture-table, some descriptions being of pale colour 

 and highly mobile, whilst others are almost black and viscid. The 

 specific gravity appears to range from 0'771 to 1*06. 



As regards its chemical composition, petroleum consists essentially 

 of carbon and hydrogen, together with oxygen, and varying amounts 

 of nitrogen and sulphur. 



Pennsylvanian petroleum consists chiefly of a large number of 

 hydrocarbons of the paraffin series, whilst naphthenes or polymethyl- 

 enes are the predominant constituents of Russian petroleum. In 

 some descriptions of crude petroleum, notably those of the Dutch 

 East Indies, Persia, and Burma, aromatic hydrocarbons are largely 

 present. 



These paraffins and naphthenes are very accommodating, in the 



