CONDENSED DEW IN- ROOMS. 239 



to detect a certain amount of chemical matter 

 in the air. A part of this was sulphuric acid, 

 with some chlorine, and an organic substance 

 resembling impure albumen. Such matters are 

 constantly being poured into the air, partly 

 from the lungs of men and animals, and from 

 manufacturing processes. On 1 these substances 

 becoming condensed upon cold bodies and in a 

 warm atmosphere, the albuminous matter very 

 soon putrifies and emits disagreeable odours. 

 The oxygen of the atmosphere acts upon it, 

 and it gives rise in its decomposition to car- 

 bonic acid, ammonia, sulphuretted hydrogen, 

 and probably other gases. The matter con- 

 densing on cold walls in crowded assembly 

 rooms may be collected by means of a little 

 tube called a pipette. If allowed to stand it 

 thickens, and on examination under the micro- 

 scope is found to contain numbers of minute 

 confervse, between the stalks of which a num- 

 ber of greenish globules are seen constantly 

 moving about, accompanied by still more minute 

 animated particles, presenting a very interesting 

 and beautiful spectacle. If this animal exhalation 

 is allowed to accumulate on various objects by 

 its frequent condensation on their surface, and 

 subsequent drying up, it forms a gummy organic 

 plaster, which may often be found upon the 

 neglected furniture of dirty houses. In moist 



