[Footnote 8: Comptes Rendus, 101, 949.]

The results of estimations of bases and carbonic acid in the water of
the English Channel lead Schloesing[9] to conclude that the carbonic
acid combined with normal carbonates, forming bicarbonates, dissolved
in the water of the globe is ten times greater in quantity than that
of the atmosphere, and on account of this available carbonic acid, if
the atmosphere should be deprived of some of its carbonic acid, the
loss would soon be supplied.

[Footnote 9: Comptes Rendus, 90, 1410.]

As, in nearly all of the methods which were employed for estimating
carbonic acid in the air, provision is not made for the exclusion of
air not measured containing carbonic acid from the alkaline fluid
before titrating or weighing, the results are generally too high and
show a far greater variation than is found by more exact methods. For
example, Gilm[10] found from 36 to 48 volumes; Levy's[11] average is
34 volumes; De Luna's[12] 50 volumes; and Fodor's,[13] 38.9 volumes.
Admitting that the quantity of carbonic acid in the air is subject to
variation, yet the results of Reiset's and Schultze's estimations go
to prove that the variation is within narrow limits.

[Footnote 10: Sitzungsher. d. Wien. Akad. d. Wissenschaften, 34, 257.]
[Footnote 11: Ann. d. l'Observ. d. Mountsouris, 1878 and 1879.]
[Footnote 12: Estudios quimicos sobre el aire atmosferico, Madrid, 1860.]
[Footnote 13: Hygien. Untersuch., 1, 10.]

Indiana University Chemical Laboratory,
Bloomington, Indiana.