1878. } The Beneficial Influence of Plants. 803 
suppose from the circumstance that the spaces between the 
molecules are so much greater in the case of the gases than in 
solids or liquids, that no such thing as the interception of rays by 
these separate particles could occur, But recent, very ingenious 
and delicate experimentation by Prof. Jno. Tyndall has placed the 
fact beyond the domain of mere reasoning, that gases do inter- 
cept radiant heat, in other words, absorb and radiate calorific 
rays. It would be outside the limits of the present writing to 
describe the apparatus used and the methods pursued. Suffice it 
to allude to the results obtained by this investigator, and the 
conclusions arrived at by him. The correctness of these results 
will doubtless be readily eee after a perusal of his admira- 
ble work on “ Radiation,” where everything is fully explained. 
In experimenting with olefiant gas and sulphuric ether vapor, 
it was found that the densities of these two gases may be reduced 
vastly below that which corresponds to the atmospheric pressure, 
and still they were capable of arresting undulations of heat. On 
investigating some of the permanent: gases, as carbon dioxide, 
nitrous oxide, etc., he found extreme variations in absorbent 
powers. The heat-absorbing capacity of hydrogen and of dry 
air were found to be inappreciably small, while carbon monoxide, 
carbon dioxide, etc., were found to be active absorbents. Con- 
sidering the absorbing capacity of dry air one, that of carbon 
dioxide, would be ninety. Experiments with ozone place this 
was reported by her physician, Dr. J. P., a victim of tubercular consumption, to 
which disease she would succumb before the coming summer. She was a lover of 
plant, and flowers, and cultivated them in-doors and out. The spring saw her again 
moving among her plants, anl the winter found her confined to the house, and some- 
times for weeks to her bed-chamber, which, like the sitting-room, was literally a 
green-house. Visitors and friends often spoke to her of the impropriety of having 
so many growing plants in her room, reminding her of the tradition that they were 
injurious. Still, every spring found her again on her feet, in the yard and garden, 
nursing her plants, and every winter confined to her room. And thus she lived, 
year after year, until two years ago when, at the age of 85, she passed away. I have 
seen a few others have plants growing and blooming in their chambers, but never one 
who so lived among them as did my sister. Winter after winter we looked for her 
death, the cough, expectoration and weakness justifying our apprehensions, and yet 
her 85th year found her pome and happy, — among her plants and enjoying 
the society of her friends. May we not believe that the vast exhalation from these 
_ plants—water purified and meils by their vital D ae her life? 
The results of your experiments will awaken :hought, and lead to observation on 
the influence of growing plants in the chambers of the sick. Truly your friend, 
HIRAM Corson, 
VOL. X1I,—No, XM. 54 
