802 
DE. SMITH ON THE ELIMINATION 
The quantity of ui’ea evolved on the 26th and the 29th was somewhat unduly increased 
by food. 
Hence, on summing up the results now obtained, I venture to state that the action, 
both of temperature and atmospheric pressure, is direct, and that the urea varies as they 
vary ; but the results are oftentimes conflicting. The following are some of the causes 
of variation from the rule ; — 
1. When the temperature increases and the pressure decreases, and vice versd. 
2. When the same cause acts for a lengthened period, the speciflc effects will be 
found only in the early days, since the necessity which exists for the maintenance of an 
equilibrium in the statics of the body induces oscillations, as the two influences are 
respectively powerful. Hence high atmospheric pressure will at first cause increased 
elimination of urinary water ; but at length a point is reached below which the fluids of 
the body cannot be reduced consistently with health, and the quantity of urine falls, as 
is seen in the last Table. 
3. Whenever, and from whatever cause, there is an increased elimination of urine, 
there will usually be an increase in the urea, notwithstanding the influence of adverse 
atmospheric influences. 
4. The effects of meteorological and other influences are frequently carried on to the 
following day ; so that in such a case there will be a modified influence acting on both 
days, and the distinction will be less perceptible; but sudden increase of pressure 
commonly caused an immediate increase in the quantity of urine evolved. 
5. The actual temperature in which we live is not that of the external atmosphere, 
and cannot be rigidly determined. 
With sudden increase of temperature and a low barometer, there is a sense of faint- 
ness and fullness, and the elimination of fluid and urea is retarded ; whilst with increased 
atmospheric pressure and decreased temperature, the bulk of the body is lessened with 
the increased emission of fluids, and there is according to the degree a sense of liglitness 
or of oppression, 
\Contrast of the daily inquiries during two consecutive years, viz. from March 1860 to 
March 1862. (Plate XXXVI.) 
The long interval which has elapsed since the preparation of this paper has permitted 
me to continue the daily inquiries through another year, and has afforded me the 
singular advantage of being able to compare the daily quantities through the several 
seasons of two successive years, and I have been permitted to add the figures to the 
Tables (p. 759 et seq.), and to represent the oppositions and agreements in the quantities 
recorded in Plate XXXVI. I now append a short Summary of the points in Avhich the 
latter year has agreed or contrasted with the former. 
Conditions of the inquiry. — During the last year the health has been as uniformly 
maintained as before ; but there has been somewhat less of bodily exertion, and the weight 
of the body has increased about ten pounds. The daily inquiries have been made with 
