1909.] Presence of Carbon Monoxide in Normal Blood, etc. 525 



insufficient to account for some of the quantities found in the experiments 

 quoted in Table II. 



It is known from the experiments of Desgrez*, and of Thiele and Dentf, 

 that chloroform is decomposable by aqueous potash in the cold with the 

 v production of carbon monoxide, and it seemed not unlikely that in this 

 reaction an explanation was to be found for the comparatively large amounts 

 of iodine evolved when U-tube (4) was in the circuit. 



That this was the case is proved by the following experiments : — 



Effect of Solid Potash on Chloroform. 



Experiment I. — Two stout test-tubes filled with mercury were inverted in 

 a bath of mercury. Into one a piece of dry solid potash was introduced, and 

 into the other a piece of potash, the surface of which was moistened with 

 water. A few drops of chloroform were then passed into each tube. In 

 both cases a slow evolution of gas commenced at once, and after standing 

 overnight 3 — 4 c.c. of gas had collected above the mercury. This gradually 

 increased in quantity until at the end of three days the tubes were almost 

 full of carbon monoxide. 



Experiment II. — In this experiment a comparison was made between the 

 quantities of iodine liberated when a 5 to 6-per-cent. mixture of chloroform 

 and air was passed over iodine pentoxide (A) with the U-tubes 4 and 5 in 

 the apparatus figured above filled with calcium chloride, (B) with the 

 U-tubes 4 and 5 filled with roughly -powdered potash, that in the first limb 

 of 4 being slightly moistened. The experiments were conducted otherwise 

 under rigidly similar conditions. The following results were obtained : — 



Expt. 



Teni]). 



Composition 

 of CHC1 3 

 and air 



Duration 

 of oxygen 

 current 



Duration 

 of oxygen 

 current 



Iodine liberated in 

 terms of N/1O0O 

 thiosulphate in 



Difference 

 between 



expt and 

 control 







mixture. 



in control. 



in expt. 



Control. 



Expt. 



in c.c. of 

 thiosulphate. 



A 



using CaCl 2 

 tubes 



°C. 

 137 



5 95 



liours. 



2 



hours. 

 2 



c.c. 

 4'4 



c.c. 

 11 -25 



6-85 



B 



using KOH 

 tubes 



137 



5 -41 



2 



2 



4-4 



185 -5 



181 -5 



* 'Comptes rendus,' 1897, vol. 125, p. 782. 



t Thiele and Dent, ' Annalen,' 1898, vol. 302, pp. 223—274. 



