54 | Scientific Intelligence. 
made in erro with the “ Pommerania ” Expedition of 1871, 
results to investigate anew the sbacspehne capacit y of sea-water 
for carbonic acid. He determined the amount contained in the 
water of the North Sea to be about 100 mgr. per liter, and of this 
he concluded that only a very small proportion was obtained 
from the bicarbonates; and further he was confident that no por- 
process. He found, however, that even when the boiling process 
was carried on under the full atmospheric pressure the carbonic 
acid, though supposed to exist in the gaseous form, escaped so 
slowly that souiseitention to about one-tenth of the original vol- 
ume was needed to obtain it all. To account for this phenom- 
enon Jacobsen. uaatibed to sea-water a peculiar power of retaining 
its carbonic acid depending, as he believed, upon the magnesium 
chloride present. This hypothesis was adopted by: dX Bo 
chanan, chemist of the “ Challenger ” Expedition, who also, as the 
result of a series of experiments, concluded further that most of 
the salts present in sea-water had this property of retaining the 
sagen acid, but most of all the sulphates. He, accordingly, 
n his determinations first Ea abet the sulphuric acid b 
atic chloride, but otherwise adopted the method of Jacobsen. 
The amount of sarees acid i sheen water of the Siashesa Seas 
he found to be 43°26 mgr. per lite 
conclusions which have been. described were, however, 
n, and his experiments lead to a very different result. Consid- 
nena it more probable that the carbonic acid obtained was derived 
from the decomposition by the protracted process of boiling of sor 
neutral carbonates present, than that it existed as a gas and w 
series of experiments to decide this point. Two hundred c. c. of 
a-water were distilled nearly to dryness eggs ong carbonic acid 
éollected 3 in baryta water; 20°2 mgr. were found to have been 
off. Freshly boiled water was now octet on the seecndus 
and it then ev speeitadl the result yielding only a trace of carbonic 
acid ; finally some purified and treshly-heated soda was added, 
Ad 
and the whole again diluted to the original volume. As soon. 
in eben so large that part passed unabsorbed through the 
baryta water. The experiment was also repeated with precipi- 
tated saiehaie carbonate, and the carbonic acid expelled from it 1m 
considerable quantities, though not so large as before. These 
mining the free carbonic acid in sea-water were inaccurate, inas- 
much as the boiling process causes a decomposition of the neutral 
in which the gaseous elements in the water were boiled out 
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