18 REPORT—1848. 
the experiment. ‘This matter condenses on the glass and walls in cold 
weather, and may be taken up by means ofa pipette. If allowed to stand 
some time, it forms a thick, apparently glutinous mass; but when this is 
examined by a microscope, it is seen to be a closely-matted confervoid 
growth, or in other words, the organic matter is converted into Conferve, as 
it probably would have been converted into any kind of vegetation that 
happened to take root. Between the stalks of these conferve are to be 
seen a number of greenish globules constantly moving about, various species 
of Volvox, accompanied also by monads many times smaller. When this 
happens, the scene is certainly lively and the sight beautiful; but before 
this occurs the odour of perspiration may be distinctly perceived, especially 
if the vessel containing the liquid be placed in boiling water. 
My analyses of this body are not yet ready, further than that it contains 
the usual organic elements. 
If air be passed through water a certain amount of this material is ob- 
tained, but I have found it difficult to pass a sufficient quantity through. 
If it is made to pass rapidly, absorption does not take place, and evaporation 
of the water is the consequence ; if it passes slowly, it requires many weeks 
to pass a hundred cubic feet through a small quantity of water. I continued 
the experiment for three months, but although I obtained sulphuric acid, 
chlorine, and a substance resembling impure albumen, I did not get enough 
to make a complete examination ; and indeed this could not be expected, as 
I found that in that time less than a thousand gallons ef air had passed 
through. 
When this exhalation from animals is condensed on a cold body, it in 
course of time dries up, and leaves a somewhat glutinous organic plaster ; 
we often see a substance of this nature on the furniture of dirty houses, and 
in this case there is always a disagreeable smell perceptible. I have no 
doubt that this is a great cause of the necessity for constant cleaning, which 
experience has found and made to be a very general practice in England and 
elsewhere. In other words, it is a reason why that which is not cleaned becomes 
dirty, a question which I have often felt great difficulty in answering. 
Water is necessary to the spontaneous decomposition of animal matter, 
and it is probable that in a warm climate this coating of walls and furniture 
would not be so dangerous as with us, where everything is exposed to 
moisture a considerable part of the year. In a warmer climate it will pro- 
bably be diffused more into the atmosphere, and not be so much retained. as 
it is by the moisture which dissolves it or to which it attaches itself. 
It will probably be found that this substance is not poisonous if taken — 
into the stomach, but it is known to be poisonous breathed into the lungs, 
as we know crowded rooms are. The quantity is small that we do breathe, 
but at the same time we must remember that it is diffused in air, and has 
therefore a surface as extended as the volume of the air in all probability; — 
and we know that a cubic inch of sulphuretted hydrogen will scent at least — 
some hundred cubic feet of air. 
As this substance of which we speak is organic and contains carbon hy- — 
drogen and nitrogen, with other elements, it is capable of oxidation; and it no — 
doubt is continually undergoing oxidation in the air, probably forming car- — 
bonic acid, water and ammonia. It is also not unlikely that this is a greater _ 
source of the ammonia of the atmosphere than the mere foetid decomposition — 
of animal matter, which does not occur to a large extent in nature, provision 
being made for its removal by animals, and by vegetation especially. 
