286 Prof. AYri^lit. In/In, m:e of Carbonic Acid ami [Mar. 



in the blood, while he ascribed the diminished coagulability which 

 observed after a lengthened application of the ligature to an excess 

 of the carbonic acid. In like manner this observer ascribes (a) the 

 increased coagulability which he obtained after holding his br. ;ith 

 for twenty seconds to an increase of C0 in his blood, (b) the dimin- 

 ished coagulability he obtained after holding his breath for forty- 

 five seconds to an excess of carbonic acid, (c) the diminished co- 

 agulability of venous, as compared with arterial, blood to the same 

 caupe, and (d) the diminished coagulability of his blood after rapid 

 respiration to an excess of oxygen. There is nothing in the experi- 

 ments to justify any of these inferences. 



Exactly the same objections can be urged against Bonne's ex] 

 ments. It will suffice to point out that Bonne obtained a diminuti< 

 of coagulability in a bare majority of experiments in pigeons in 

 which asphyxia was produced by the inspiration of carbonic acid, nn< 

 that he interprets this diminution of coagulability as an effect ol 

 the excess of carbonic acid tension, while the anoxyhaemia to whi< 

 the animals succumbed is entirely left out of sight as a possibl 

 factor in the causation. 



Lastly, the work of Mathieu and Urbain comes up for noti< 

 These observers conjointly investigated the effect of carbonic acid 

 upon blood coagulability, and came to the conclusion that carbonic 

 acid was a very important, if not indeed the all-important, agent in*j 

 the production of blood coagulation. This conclusion was based 

 upon the following observations : (a) Blood coagulation is accom- 

 panied by a giving off of something like 50 per cent, of the carbonic 

 acid originally present in the blood ; (6) an artificial increase of the 

 body temperature goes hand in hand with a diminution of the carb- 

 onic acid and with an increase in the oxygen in the blood, and this 

 artificial increase of the body temperature results in a diminished co- 

 agulability ; (c) the blood from the renal vein, which resembles in its 

 gaseous composition the blood of the superheated organism, is charae* 

 tensed by a similar diminished coagulability ; (d) an artificial redu< 

 tion of the body temperature goes hand in hand with an increai 

 of carbonic acid, which is quantitatively comparable to the increase 

 which is produced by asphyxiating an animal by C0 2 . This increase 

 of carbonic acid in the blood under the influence of cold goes hand in 

 hand with an increased blood coagulability ; (e) when blood is pre- 

 vented from clotting by the addition of a few drops of ammonia (the 

 ammonia is assumed to retard coagulation by binding the free carb- 

 onic acid), and when a new formation of carbonic acid is prevented 

 by eliminating the oxygen from the blood by a stream of CO. the 

 blood is found to have lost its spontaneous coagulability. Such blood 

 becomes coagulable when a stream of COj is passed through it ; 

 (f) strong solutions of neutral salts have a large absorbing power for 



