Natural History. 179 



Chaumlec and Chumbuljoin, had occasion to observe the production 

 of this alkali in considerable quantities in the bed of the river. It 

 being the dry season there was scarcely any streain, but a number 

 of pools, and walking amongst them, " I observed that, on the 

 margin of one of the above pools, the ground for a considerable 

 space appeared beautifully white ; on examining it closely, I found 

 it covered with a fine pure saline efflorescence, in general about two 

 or three tenths of an inch in depth, covering a soft, wet, and slip- 

 pery mud ; the taste and appearance of this salt induced me to con- 

 clude it was carbonate of soda, which I found to be the case on 

 taking some of it to my tent." Before Captain Stewart could ascer- 

 tain the extent of the bed, an order came for removal; but he believes 

 there are numberless places in tlie bed of the river besides the one 

 he discovered, and thinks they might be easily and profitably worked 

 in the dry season. The banks of the river are described as steep 

 and broken, and composed of a kind of friable clay-rock, mixed 

 with loose limestone. The bed of the river is in many places ba- 

 saltic rock, sometimes forming a smooth surface, exhibiting the pen- 

 tagonal form of the columns like a regular pavement. — Bombay 

 Trans, iii. 53. 



4. Acid Earth of Persia. — An acid earth is found in great quan- 

 tities at a village, called Daulakie, in the south of Persia, between' 

 three and four days' journey from Bushire, on the Persian Gulf. It 

 is used by the natives in makiug their sherbets, ^c, and large quan- 

 tities are thus employed. A portion has been brought from thenca 

 by Lieutenant-Colonel Wright, and examined by Mr. Pepys, who 

 finds that about a fifth of it is soluble in boiling water, yielding an 

 acid solution, which, when tested, gave proofs of the presence of 

 sulphuric acid and iron, and on evaporation yielded crystals of aci- 

 dulous sulphate of iron. — Phil. Mag. lxii. 75. 



5. A most extraordinary experiment has been made by M. 

 Dobereiner. It was communicated to me by M. Hachette, and hav- 

 ing verified it, I think every chemist will be glad to hear its nature. 

 It consists in passing a stream of hydrogen against the finely divided 

 platina, obtained by heating the muriate of ammonia and platina. In 

 consequence of the contact, the hydrogen inflames. Even when the 

 hydrogen does not inflame, it ignites the platina in places; and I find 

 that when the hydrogen is passed over the platinum in a tube, no air 

 being admitted, still the platinum heats in the same manner. What 

 the change can be in these circumstances, M. Dobereiner has, no 

 doubt, fully investigated; and the scientific world will be anxious to 

 hear his account of this remarkable experiment, and the consequences 

 it leads to. — M. F. 



6. Organic remains in Poland. — In a calcareous rock of the moun- 



N 2 



