DESERT. 83 
this might be caused by snow blown from them by 
the wind, but later in the day almost all the peaks 
presented this appearance, and I believe it was chiefly 
owing to clouds forming on them. 
On the 26th July we marched seventeen miles to 
Patsalung, and finding a little grass we halted next 
day to recruit our surviving horses, for many had 
been abandoned, and our riding horses had now to be 
pressed into the service to carry loads. 
On the 28th July we marched fifteen miles to Lung 
Dung, nearly ten miles of the way being over a plain 
about five miles wide, which was covered to a depth 
of many feet (in one place where cracks existed to 
not less than twenty feet) with sulphate of magnesia* 
(Epsom salts), pure and white as newly-fallen snow. 
It caused a glare which was most painful to the 
eyes, and irritated the face and hands ; for the cold 
winds had taken nearly all the skin ofi" our hands and 
faces, and the only way in which we could travel in 
any comfort when the wind was blowing was to have 
a cloth over the face with holes cut out for the 
eyes and mouth, and long sleeves to protect the 
hands. On the surface of the plain the salt had 
efiloresced and become an impalpable powder, which 
rose in clouds as the horses waded through it, some- 
times up to the knees. Underneath it was hard and 
crystalline, and crackled under the horses' feet. At 
intervals, probably where springs existed, there were 
lakes of strong brine, on which I observed numbers of 
the Euddy Shieldrake (Casarca rutila) and plover. For- 
* Dr. FranklaDd has examined a specimen of this salt, and finds that it is pure 
sulphate of magnesia, without a trace of any other salt. 
G 2 
