152 DOMAIN IX. ANOMALOUS. 



appetite, especially if a small quantity is also 

 drank."* 



The justly celebrated Kempfer had visited 

 these remarkable springs in the end of the seven- 

 teenth century ; and Gmelin, in the eighteenth 

 century, 1773, has added little to the account 

 of Hanway, except that the soil is a coarse mar), 

 mixed with sand, and effervescing with acids. 

 There are many other wells in an adjoining pe- 

 ninsula ; and the revenue arising from this un- 

 common product, to the khan of Baku, was 

 computed at forty thousand rubles. 



Werner rather doubts the existence of pure 

 and limpid rock oil, and unites naptha with 

 petrol : the purer kind indeed seems to occur 

 only in small quantities. The mineral tar of 

 Colebrook Dale is obtained from a sandstone: 

 and Williams has observed many bituminous 

 rocks in Scotland. Bituminous shale and marl 

 are not uncommon ; but the whole subject re* 

 quires and deserves further illustration. 



HYPONOME I. 



Limestone with naptha, or with petrol. 



* Hanway's Travels, i. 263. 



