390 Prof. Johnston on the Composition of certain 



Moldavia*, in sufficient quantity to be employed for oecono- 

 mical purposes, and to which the name of Ozocerite has been 

 given. This substance is of a brown colour, of various shades, 

 has the consistence and translucency of wax, a weak bitumi- 

 nous odour, sometimes a foliated structure and conchoidal 

 fracture, and can be reduced to powder in a mortar. In 

 burning, it emits considerable light, and is said to be used 

 for the manufacture of a species of candles. 



The chemical and physical properties of this substance were 

 first examined by Magnus [Ann, de Chem. et de Phys., Iv., 

 p. 218) ; more lately by Schrotter [Bibliotheque Univ., May, 

 18S6); and most recently by Malaguti {Ann. de Chem., Ixiii. 

 p. 390) ; who agree in representing it as a mixture of several 

 substances, differing in their physical properties, yet possess- 

 ing the same ultimate chemical constitution. 



The occurrence of a fossil body, possessing many of the 

 characters of Hatchetine, and having much resemblance to 

 the fossil wax of Moldavia, in a coal mine in this neighbour- 

 hood, where no doubt could exist as to its origin, has afforded 

 me an opportunity of adding to our knowledge of this class of 

 mineral compounds, while it seems to indicate pretty clearly 

 their common organic origin wherever they may occur. 



In driving through a trouble in Urpeth Colliery, at a depth 

 of about 60 fathoms from the surface, this substance was found 

 in cavities near the sides of the trouble, and sometimes in the 

 solid sandstone rock; it occurred in considerable quantity, 

 and was sufficiently soft to be made up into balls by the 

 workmen. 



The specimen sent to me by my friend Mr. Hutton, of 

 Newcastle, is soft, unctuous, sticking to the fingers, and 

 giving a greasy brown stain to paper; semi-transparent; by 

 transmitted light, of a brownish yellow colour ; by reflected 

 light, yellowish green and opalescent ; having a slight fatty 

 odour, more perceptible when the substance is melted. It 

 fuses at 14<0° Fahr., attains its greatest fluidity at about 160°, 

 and begins to boil at 250°. It distils without apparent de- 

 composition, the colourless oil which passes over concreting 

 as it cools into a colourless unctuous mass. As it distils, 

 however, the boiling point of the residue rises very consider- 

 ably, and it becomes darker coloured. Boiled in a retort with 



* It is found, according to Dr. Meyer, at the foot of the Carpathians 

 near Slanik, beneath a bed of bituminous slate clay, in masses sometimes 

 from 80 to 100 pounds weight. Not far from the locality are several 

 layers of brown amber. It is associated with the gres bigarre, with rock 

 salt, and with beds of coal. 



