Cox. — On the Mineralogy of New Zealand. 377 



a mawkish but not unpleasant odour, being very different in this respect 

 from most rock oils, and is especially free from all traces of sulphuretted 

 hydrogen. Minute flakes of a white substance float in the oil, and are 

 gradually deposited when it is allowed to remain quiet at a low tempera- 

 ture, nearly the whole of this solid substance becoming dissolved when the 

 oil is gently heated. Boils at 340° Fahr., and does not appear to evaporate 

 at ordinary temperatures. Vapour inflames at 260° Fahr. ; does not con- 

 tain paraffin. Very valuable as a lubricant on account of its low freezing 

 and high volatilizing points. 



2. Poverty Bay. — A true paraffin oil. Opalescent and thickly inter- 

 spersed with minute flaky particles of a white colour ; by warming the oil 

 gently these particles subside, and the oil manifests the following cha- 

 racters : translucent in masses of considerable thickness ; colour, red by 

 transmitted and blackish-green by reflected light ; flows readily and gives 

 off the usual odour of crude petroleum. Its boiling-point at 30 ins. baro- 

 metric pressure varies from 289° to 291° Fahr. The temperature at which 

 the vapour inflames is from 230° to 233° Fahr., and sp. gr. from "864 to 

 •871 at 60° Fahr. Passes into a jelly-like mass at 50° Fahr., owing to the 

 quantity of paraffin dissolved in the oil. 



3. Manutahi, Waiapu Paver. — Is the lightest natural mineral oil known 

 in the colony. Colour, pale brown ; nearly or quite transparent ; does not 

 manifest a green-black colour by reflected light ; flows with great freedom ; 

 has the odour of kerosene ; sp. gr. # 8294 at 60° Fahr. ; burns well in a 

 kerosene lamp for some time. Contains only traces of paraffin, and does not 

 acquire any increased consistency when the temperature is lowered to 8° Fahr. 



For details concerning the constitution of these oils I must refer the 

 reader to the paper above cited, and also to another by the same author 

 (Trans. N.Z. Inst., vol. xi., p. 469). 



Dopplerite. — A mineral grease resembling dopplerite was collected by 

 Dr. Hector from Waiapu in 1872, and during 1880 a specimen of the same 

 mineral was forwarded to the Colonial Laboratory for examination on the 

 supposition that it was ozokerite or native paraffin. 



This substance is of a soft greasy nature, brownish-yellow colour, and 

 possesses a strong odour of paraffin. It burns readily with a smoky flame, 

 leaving a large quantity of ash, and consists, according to Mr. Skey (Trans. 

 N.Z. Inst., vol. xiv., p. 398) of 3-1 per cent, oils ; 9'3 per cent, paraffin ; 

 26*9 per cent, earthy matter; 11-3 per cent, water; and 49"4 per cent, 

 oxygenated hydro -carbons. 



Ozokerite, CH. — This mineral is mentioned by Dr. Hector (Jurors' Kep. 

 N.Z. Ex., 1865, pp. 267, 438) as occurring in the brown coals of Dunstan, 

 Otago. "We have, unfortunately, no specimen of this. 



