156 REPORT—1858,. 
lands, especially in or near the tropics, had been forced to reflect on the changes of 
climate that appeared to have occurred. There were parched and barren lands, dry 
river channels, and waterless lakes, and not unfrequently traces of ancient human 
habitations, where large populations had been supported, but where all was now 
desolate, dry, and barren. He had been first led to a consideration of the subject by 
phenomena of this nature that had come under his own observation, particularly in 
Australia, and he soon discovered that desiccation, so very observable there, was 
too extensive and permanent to be explained by occurrences of an irregular nature. 
Remembering also that similar appearances had been observed in other parts of the 
world, for which no satisfactory cause was assigned, he had collected the observa- 
tions of travellers in regard to various countries, and endeavoured, by the evidence 
they afforded in the failing of the water systems, to establish the theory of a general 
and continuous decline of the humidity supported by the atmosphere, and then to 
discover in the operation of some law of our terrestrial system the cause of desicca- 
tion in both land and atmosphere. After quoting largely from the works of various 
travellers and writers (amongst the latest of whom were Dr. Livingstone), and 
giving interesting descriptions of dried-up rivers and desolated tracts of country in 
Australia, Africa, Mexico, and Peru, which had formerly been inhabited by man, 
Mr. Wilson proceeded to give his own theory as to the cause of this desiccation, con- 
tending that the upheaval of the land, the waste by irrigation, and the destruction 
of forests, all of which had been put forward as the cause, were insufficient to 
account for what had been described. He remarked that the amount of aqueous 
vapours that can be borne by the atmosphere at any time must be in proportion to 
the mass of the atmosphere itself, from which it followed that a reduction in the 
mass of the atmosphere would produce a corresponding decline in the amount of 
hydrous vapours absorbed and supported. If, therefore, a physical operation, in- 
volving a waste of the atmosphere, could be discovered, it might be concluded that 
at least one cause had been found for its declining humidity. Agreeably with these 
conditions, it was learnt that a vast amount of the atmosphere, and of the ocean like- 
wise, had been solidified. The rocks, in the history of their own formation, bore 
witness to the tendency to transmutation in the character of both. The elements of 
water were hydrogen and oxygen, and the atmosphere was composed of oxygen, 
nitrogen, and carbonic acid, in which hydrous vapours mingled in varying quantities, 
all of which had entered largely into the formation of rocks and minerals. The coal 
plants had absorbed largely all the elements of air and water, but particularly of 
carbon, of which coal contains on an average from 80 to 90 per cent. Carbon united 
with oxygen formed carbonic acid, which, combined with lime and solidified, formed 
more than two-fifths of all limestone rocks. Oxygen was said to form half of what 
is known of the material of the globe. Besides existing in air and water, it formed 
a part of most earthy substances, and of nearly all the productions of the animal 
and vegetable kingdom. The oxygen of the atmosphere was also gradually absorbed 
by all animal and vegetable productions, and by almost all mineral masses exposed 
to the open air. From such facts as he had adduced and others he could produce, 
Mr. Wilson concluded that there was a gradual solidifying of the atmosphere and 
water on the face of this terrestrial world, which he inferred was, in the usual course 
of geological changes, slowly approaching a state in which it will be impossible for 
man to continue an inhabitant ; and remarked that as inferior races preceded man 
and enjoyed existence before the earth had arrived at a state suitable to his consti- 
tution, it is more than probable others will succeed him when the conditions neces- 
sary for his existence have passed away. 
Notice of the Opening of a Sepulchral Tumulus in East Yorkshire. 
By Tuomas Wricut, M.A. 
Setting aside the vague speculations on a pre-Celtic population of the island, the 
first Roman known to have visited it, Julius Cxsar, who appears to have been 
personally acquainted only with the latter settlers in the maritime district of the 
south-east, informs us that the interior was inhabited by a people much inferior 
in cultivation, who were reputed to be the original inhabitants of the island. This 
people, we learn from later writers, were called the Brigantes, who held a very 
