BULLETIN OF THE BUSSEY INSTITUTION. 211 
experiment, and afterwards 1,200 cc. of pure water; but the reactions 
for carbonic acid and for lime persisted to the end. 
The interference of the loam with the action of the carbonic-acid water 
was still further illustrated in the following quantitative experiment, which 
was made in the hope of gaining some slight idea of the amount of lime 
that was dissolved from the loam by carbonic-acid water. 1,000 ce. of 
the dry store-room earth were percolated with carbonic-acid water, each 
50 cc. fraction of the percolate was supersaturated with dilute standard 
acid, and the amount of this acid neutralized by matters in the percolate 
was determined by titrating back with a tenth-normal solution of borax. 
It appeared that the following amounts of acid were neutralized by the 
several fractions of percolate, from the first to the fifth respectively; 
viz., 0.7 cc., 0.9, 1.0, 1.0, and 1.2. 3800 cc. of percolate were then 
allowed to flow to waste, and afterwards, three other fractions were tested 
with acid, with the following result. These new fractions were each of 
100 cc. : the first neutralized 2.5 ce. of acid; the second, 2 cc., and the third, 
2.5 cc. The acid employed was nitric, one-tenth normal. Each centi- 
metre of it was equivalent to 0.0028 grm. CaO, or to 0.005 grm. CaO, 
CO. 
Other experiments were made in this connection by percolating quanti- 
ties of similar earth with a solution of carbonate of lime in carbonic-acid 
water. In one trial, where 1,000 cc. of earth were taken, and the lime 
solution employed was of such strength that 50 ce. of it neutralized 7 cc. 
of the acid, the first six fractions, each of 50 cc., neutralized the follow- 
ing amounts of the acid; viz., 1.2 cc. 1.8, 1.5, 1.5, 1.6, and 1.6. In 
another trial, where 250 ec. of the earth were taken, and 50 ce. of the 
original lime solution neutralized 6.9 cc. of the tenth-normal acid, the 
first ten fractions of the percolate neutralized respectively 1.5 cc., 1.7, 
2.2, 2.4, 2.5, 2.6, 3.5, 4.0, 5.0, and 7.0 cc. of the acid. 
On percolating 1,800 cc. of pure dry Berkshire sand with carbonic-acid 
water, the very first portions of the percolate gave the reactions of car- 
bonic acid. 500 cc. of the carbonic-acid water were gradually poured in 
at the top of the cylinder (of 46 & 7cm.), and nearly 75 cc. of liquid 
came through; i.e., 425 cc. were absorbed by the sand. ‘The sand thus 
moistened with carbonic-acid water was then percolated with pure water, 
and the reactions of carbonic acid were obtained in the percolate up to 
1,000 ce., when the apparatus was left to stand over night: on percolating 
again next morning, the first 50 cc. of liquid gave no reaction for car- 
bonic acid. 
In another experiment, dry Berkshire sand was saturated with about 
400 cc. of pure water, and then percolated with carbonic-acid water. ‘The 
reactions of carbonic acid were obtained when 450 cc. of percolate had 
been collected. 
It would seem to be plain from all the experiments here cited, that 
when carbonic-acid water comes in contact with moist earth it is de- 
