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flask surrounded by ice and salt, by which a temperature 
of several degrees below zero was obtained. The fluid 
collected was then analysed for free ammonia, urea and 
kindred substances ; and for organic ammonia — the method 
employed being that invented by Messrs. Franklyn and 
Chapman foi; water analysis. 
The breath of 11 healthy persons and of 17 affected by 
different disorders was thus examined, and the results were 
given in two tables. 
The persons examined were of different sexes and ages, 
and the time of the day at which the breath was condensed 
varied. 
In both health and disease the free ammonia varied 
considerably, and the variation could not be connected with 
the time of the day, the fasting or full condition. Urea 
was sought for in 15 instances — three healthy persons and 
12 cases of disease — but it was only found in two cases of 
kidney disease, in one case of diphtheria, and a faint indica- 
tion of its presence occurred in a female suffering from 
catarrh. 
The quantity of ammonia, arising from the destruction of 
organic matter, also varied, possibly from the oxidation of 
albumenous particles by the process of respiration ; but in 
Wealthy persons there was a remarkable uniformity in 
the total quantity of ammonia obtained by the process. 
Amongst adults the maximum quantity per 100 minims of 
fluid was 0'45 of a millogramrne, and the minimum was 0*35. 
A rough calculation was given of the total quantity of 
organic matter passing from the lungs in 24 hours — in adults 
about 3grs. in lOoz. of aqueous vapour, a quantity small in 
itself, but sufficient to make this fluid highly decomposible, 
and ready to foster the growth of the germs of disease. 
In disease there was much greater variation in the 
amount and kind of organic matter given off. 
In 3 cases of Catarrh, 1 of Measles, and 1 of Diphtheria, 
the total ammonia obtained was much less than in health — 
less than 0*2 of a millogramrne — a result probably due to the 
