of Edinburgh^ Session 1865 - 66 . 631 
(one of about 50°), is also that at which the deliquescent process of 
putrefaction ceases and the mould-growth takes its place. 
2. Of a Moist or Vaporous state of Atmosphere as modifying Change. 
The influence of warmth and moisture of atmosphere in pro- 
moting the putrid decomposition of animal matter is an established 
fact. It is well known that within the tropics, especially in littoral 
regions where the thermometer ranges between 78° and 83° or 84°, 
and the atmosphere is commonly damp, the difference between the 
moistened and dry bulb seldom exceeding 5° or 6°, putrefaction is 
so rapid that meat cannot be kept more than a few hours without 
acquiring a putrid taint. When, however, the air is very dry, as 
in Nubia and the African deserts, then the putrefactive process is 
very much arrested, though the temperature may be high. At 
Malta a wind occasionally prevails, — a south-west wind, coming from 
Africa, — which, in the summer season, I have known as high as 
105°, and so dry that the difference between the moistened and dry- 
bulb thermometer has been as much as 30°. The atmosphere of 
Nubia is somewhat of the same character ; and its quality, as to the 
checking of the putrefactive change, is well shown by a passage in 
a very charming book by a lady, — Lady Duff Grordon’s “ Letters 
from Egypt,” 1863-65 ; writing from that country, Nubia, she re- 
marks : ‘‘ Fancy that meat kept ten and fourteen days under a sun 
which I was forced to cover my head before ! In Cairo you must 
cook your meat in two days ; in Alexandria as soon as killed, and 
the sun is nothing there. Lut in Nubia I walked till I wore out 
my shoes and roasted my feet : and I was as dry as a chip in Nubia 
and as low down as Kine, below Thebes someway ; after, it altered, 
and, though cold, I perspired again.” I may mention another strik- 
ing example. In the early spring of 1826 I visited the G-reek island 
of Ipsara, a little more than two years after it had been invaded 
and devastated by a merciless Turkish force.* We found it a desert, 
the town in ruins, only one of the inhabitants remaining, who served 
as our guide, all the rest, excepting those who escaped in their ships, 
or were captured and enslaved, having been massacred. On one 
side of the island, exposed to the south-east wind, the moist sirocco. 
4 N 
VOL V. 
^ This was in June 1824, about midsummer. 
