214 Mr. Davy on the State of the Air [Mabck, 



Article IX. 



Experiments and Observations upon the State of the Air in the 

 Fever Hospitals of Cork, at a Time wlien they icere crowded 

 with Patients, labouring under Febrile Contagion. By Ed- 

 mund Davy, Esq. Professor of Chemistry, and Secretary to 

 the Cork Institution. 



[The following experiments originally appeared in the Cork 

 Intelligencer, Dec. 9, 1817; their accuracy and importance 

 appeared, however, to the Editors, to render them proper for 

 transcription into the Annals.'] 



From numerous experiments made on air, collected in dif- 

 ferent countiies, by the mo6t enlightened inquirers, it seems to 

 be generally admitted, that the chemical constitution of the 

 atmosphere is nearly the same at all seasons of the year, and in 

 all parts of the globe. Nitrogen and oxygen gases form its 

 principal component parts : it also contains a minute portion of 

 carbonic acid gas, and a variable quantity of aqueous vapour. 

 As oxygen gas is essential to animal and vegetable life, and to 

 the processes of combustion, fermentation, &.c. ; and as it is 

 constantly entering into new forms, by which its peculiar pro- 

 perties are modified or destroyed, it is considered the most 

 important, and the most active part of the atmosphere. The 

 most general and important change that the oxygenous portion 

 of the air undergoes is its conversion into carbonic acid gas, a 

 substance, which, though obnoxious to animals, is yet made 

 subservient to vegetable life; and this change is invariably 

 connected with the exertion of the vital functions of organic 

 beings, and with the burning of coals, wood, candles, &c. The 

 salubrity and healthy state of the air depend, in a great measure, 

 upon the quantity of oxygen gas it contains ; and this quantity 

 (about 21 per cent.) appears to exist in all places exposed to the 

 free atmosphere and the influence of winds. But the same 

 uniformity of composition does not prevail in the air of confined 

 dwelling houses, crowded theatres, and hospitals, that are badly 

 ventilated. At a time when typhus was very prevalent in Cork, 

 and there were in the two Fever Hospitals about 280 patients, 

 labouring, for the most part, under febrile infection, it occurred 

 to my friend Dr. Daly, whose active exertions in the cause 

 of humanity are well known, and likewise to myself, that it 

 would be a desirable object to ascertain the state of the air in 

 the fever wards ; and I immediately undertook a series of expe- 

 riments on the subject. To give in detail all the minutiae of my 

 experiments, would far exceed the limits of this paper ; I shall, 

 therefore, briefly" notice my methods and results, and close the 

 communication with a few observations connected with the subr 



