Contribution to the PhA'Siologj"^ of Respiration under tlie Arctic Climate. 85 



quantity of mercury could run out during the experiment. On the 

 basis of experiments made by Hasselbalch^ I5 assumed that the mer- 

 cury would in this way run our sufficiently regularly. 



The analysing apparatus was a transportable apparatus 

 for the determination of carbonic acid, as described by Krogh ^. In 

 accordance with advice from Krogh the apparatus was modified a 

 little, so that it could be conveniently employed for the analysis 

 both of atmospheric and expired air. The changes were, that the 

 burette, instead of at once narrowing below to a capillary tube, first 

 passed into a somewhat wider tube than the narrow one and with 

 different divisions. Similarly, the absorption pipette was continued 

 upwards into a somewhat wide tube before being drawn out into a 

 millimeter lube; a circular mark was made both on the wide and 

 on the narrow part of the tube. 



The wide tube of the burette was divided into divisions of about 

 1 cc, marked from above downwards with the numbers 6 to 1, 

 each of these being again divided into 10 divisions. Tenths of these 

 could with certainty by read, twentieths are included in the calcu- 

 lation of the analyses; but owing to possible differences in the shape 

 of the mercury meniscus, parallax etc. we must allow for a possible 

 error of + 01 of a division. Such an error, however, has not a 

 disturbing influence on the results, when these are given to 2 deci- 

 mal places. The error was reduced and the work made easier, 

 when I had gradually accustomed myself to place the mercury 

 column al once at a definite mark; this can be done with great 

 accuracy. The narrow tube was divided into 20 parts and each of 

 these was again halved by a partial line; tenths of such an interval 

 could be read with certainty. 



The calibration of the burette at the Physiological Laboratory 

 of the University before leaving gave the following result: 



Total volume (tap.— 0) 60060 cc. 



6—5 1005 



5-1 40231 



1 — 20 (between wide and narrow parts) 07585 



20—0 019702 - 



A division of the wide part of the tube 01005 



— - - narrow - - - — 0009851 - 



Analysis of the expired air was then carried out by leading so 

 large a volume of air from the sampling-receiver over into the 



^ 1. с p. 7. 



- Meddelelser om Grønland. Vol. XXVL Kjøbenhavn 1904, p. 345. 



