Miscellaneous. 439 
belongs exclusively to the salt water, Mysis relicta of Lovén, one of 
those extraordinary relics of the glacial period whose presence in 
some of the great inland lakes of Sweden has lately excited so much 
interest. I found it in small numbers at Stigersand, below Skreifjeld, 
in from 8-10 fathoms, just in the corner where a sandbank slopes 
steeply up from the deeper water beyond. 
* Associated with it, I found numerous examples of a species of 
Gammarus which at the very first glance differed markedly from the 
form I had previously noticed, and which seems to be the Gammarus 
cancelloides of Gerstfeldt, which was first discovered in the Seas of 
Baikal and of Angara, and which has lately been also found in 
Sweden, and which Lovén likewise considers originally to have 
belonged to the sea.” 
On the Expulsion of the Carbonic Acid from the Blood during 
Respiration. By Dr. Lupwic. — 
As less-carbonic acid is present in arterial than in venous blood, the 
elimination of this carbonic acid during respiration must be ascribed 
either to the oxygen or to the tissue of the lungs. For the decision 
of this question a series of experiments was undertaken, in which this 
gas was collected from unaltered venous blood, and also from venous 
blood which had been agitated with air containing oxygen. The 
blood agitated with oxygen was found to have lost its carbonic acid 
to such an extent that its amount of this gas was only equal to that 
contained in arterial blood. There is consequently no reason for 
regarding the pulmonary tissue as the cause of the evolution of 
carbonic acid. 
When the unaltered venous blood was left for twenty-four hours in 
ice-cold water and then analyzed, it appeared that in this case also the 
amount of carbonic acid was diminished. The same process therefore 
takes place in blood poor in oxygen as in that which contains oxygen 
in abundance, but with this difference, that what takes place very 
completely and in a short time in blood rich in oxygen is effected 
very gradually in that which is poor in that element. 
To determine whether the evolution of carbonic acid is effected 
directly by the oxygen, or only by the intervention of the blood- 
corpuscles, the purest possible serum, which, as is well known, con- 
tains much carbonic acid, was employed—and, for the sake of com- 
parison, both unaltered serum and such as had been agitated with 
oxygen. In these experiments the same quantity of combined 
carbonic acid was found in every case, and consequently only that 
portion of the oxygen which has passed into the corpuscles acts in 
the evolution of carbonic acid. 
As arterial blood may thus be prepared artificially from venous 
blood, it was natural to try whether the reverse of this process could 
be effected. This, however, appears to be impossible. For when the 
oxygen was pumped out of arterial blood and replaced by a quantity 
of carbonic acid equal to that which usually occurs in venous blood, 
the amount of combined carbonic acid in the blood could not be 
increased. Hence it follows that carbonic acid is furnished in the 
