28.61 | Snowing.
" 7 | 744.5 | 28.63 | Clear, snow on ground.
" 8 | 748 | 27.59 | " thawing.
" 9 | 747.5 | 28.10 | " "
" 12 | 744 | 28.04 | Cloudy.
" 13 | 744 | 28.10 | Clear.
" 14 | 743.5 | 28.98 | "
" 15 | 750.5 | 28.17 | Raining.
" 19 | 748 | 28.09 | Clear.
" 20 | 746 | 27.72 | "
" 21 | 746 | 28.16 | "
" 22 | 741.5 | 27.92 | "
" 23 | 740 | 28.12 | "
" 24 | 738.5 | 28.15 | "
" 25 | 738.5 | 27.46 | "
" 28 | 738 | 27.34 | "
--------+----------+--------------+------------------------

The average number of volumes of carbonic acid in 100,000 volumes of
air is 28.16, the maximum number is 28.98, and the minimum 27.34.
These results agree with estimations made within the last ten or
fifteen years. Reiset[2] made a great number of estimations from
September 9, 1872, to August 20, 1873, the average of which is 29.42.
Six years later[3] he made many estimations from June to November, the
average of which is 29.78. The average of Schultze's[4] estimations is
29 2. The results of estimations of carbonic acid in the air, made
under the supervision of Munz and Aubin[5] in October, November, and
December, 1882, at the stations where observations were made of the
transit of Venus by astronomers sent out by the French government,
yield the average, for all stations north of the equator to latitude
29 deg. 54' in Florida, 28.2 volumes carbonic acid in 100,000 volumes air,
and for all stations south of the equator 27.1 volumes. The average of
Claesson's[6] estimations is 27.9 volumes, his maximum number is 32.7,
and his minimum is 23.7. It is apparent, from the results of
estimations of carbonic acid of the air of various parts of the globe,
by the employment of apparatus with which errors are avoided, that the
quantity of carbonic acid is subject to slight variation, and not, as
stated in nearly all text books of science, from 4 to 6 volumes in
10,000 volumes of air; and it is further apparent that the law of
Schloesing[7] holds good. By this law the carbonic acid of an
atmosphere in contact with water containing calcium or magnesium
carbonate in solution is dissolved according to the tension of the
carbonic acid; that is, by an increased quantity its