572 
SECOND REPORT-1832. 
so constructed, that the whole gasometer would be surrounded 
with ice for some hours before the air was weighed. 
A table was exhibited containing the results of 87 experi¬ 
ments, conducted as above, between the 16th of December 
1831, and the 24tli of March 1832. The experiments were 
usually made about noon, and as nearly as possible under similar 
circumstances. The following is a summary of the results : 
The mean of all the experiments (with one exception, to be 
presently noticed,) is, that one hundred cubic inches of dry 
atmospheric air, free from carbonic acid, at the temperature of 
32°, barometer 30 inches, in the latitude of London, weigh 
32*7958 gr. ; the extreme differences between the highest and 
the lowest observations being *0507 gr. The mean of the first 
forty-four experiments, between the 16th of December and the 
8th of February inclusive, is 32*7900 grs.; the mean of the last 
forty-four, between the 10th of February and the 24tli of March 
inclusive, 32*8018 grs. ; the difference between the two series 
being *0118 gr. 
The exception alluded to above occurred on the 9th of Fe¬ 
bruary, on which day the weight of the air was 32*8218 grs. : 
and it is remarkable that after this period, during the whole 
time that the experiments were continued, the air almost uni¬ 
formly possessed a weight above the usual standard ; so that, 
as above stated, the mean of the 42 observations after this 
crisis, exceeds the mean of the 44 preceding it by no less than 
*0118 gr. The apparatus employed, and the care taken, were 
the same throughout, and there can be no doubt that the differ¬ 
ence, whatever it depended on, really existed, and did not arise 
from error of experiment. How the circumstance is to be ex¬ 
plained, it is difficult to form a conjecture ; but perhaps it may 
be worth while to observe, that almost precisely at the period 
above mentioned, the wind veered round to the north and east, 
where it continued for a considerable time, and that under these 
circumstances the epidemic cholera first made its appearance in 
London. It would seem, therefore, as if some heavy foreign 
body had been diffused through the lower regions of the atmo¬ 
sphere about this period, and which was, some how or other, 
connected with the disease in question. The action of this 
body is quite unknown ; but it could have scarcely possessed 
acid or alkaline properties, as in the former instance it would 
have been separated by the lime water, and in the latter by the 
sulphuric acid. We may probably consider it as a variety of 
malaria ; and what renders the conjecture the more likely, are its 
