60 
SECT. XII. 
VII. WHETHER OXYGEN IS SUPPLIED TO SEEDS THROUGH 
ANY OTHER MEDIUM THAN WATER PERCOLATING 
THE EARTH? 
To thy lov’d theme return, my happy muse. 
For now, behold, the joyous winter-days 
Frosty, succeed; and through the blue serene, 
For sight too fine, th’ ethereal nitre flies; 
Killing infectious damps, and the spent air 
Storing afresh with elemental life .... 
’Tis the air that j feeds and animates our Hood . 
All Nature feels the renovating force 
Of winter, only to the thoughtless eye 
In ruin seen. The frost-concocted glebe 
Draws in abundant vegetable soul, 
And gathers vigour for the coming year. 
Thomson. 
The poet, from whose immortal work on the Seasons I have selected my 
motto, approaches so near to what are styled the new doctrines relative to 
the influence of the atmosphere on the blood,* and even on the earth, that I 
should have been almost inclined to think he had derived his notions from 
Mayow, the philosopher of the last century, unless they had differed as to 
the season when this sublime process of Nature is chiefly carried on. 
Mayow had taught, that the earth became fruitful from the absorption 
of nitro-aerial particles, and founds his opinion on the following observations. 
“ Among the principles of natural things, the nitro-aerial particles 
(which is one of the component parts of nitre,-f derived to it from the air) 
* Vide the Philosophy of Medicine, or. Medical Extracts on the Nature of Health and Disease; 
including the Laws of the Animal Economy, and the Doctrines of Pneumatic Medicine, by the Author 
of this work, in five thick volumes octavo. 
f ^ tiRS been computed by the Abbe Fontana, that a pound of nitre, calcined in a close vessel, 
yields 12,000 cubic inches of OXYGEN, or VITAL, AIR. It is singularly curious that a substance 
of such "veiy humble pretensions as common nitre (salt-petre) should possess properties on which hangs 
the fate of the most powerful empiies! Since by chemistry it may either be converted into a fulmi- 
