520 Messrs. Buckmaster and Gardner. Supposed [Aug. 12, 



In another series of experiments mixtures of 500 c.c. of air and 1 c.c. of 

 carbon monoxide = 0'2 per cent, by volume were used. 



Volume of mixture 

 employed in c.c. 



50 Hb + CO recognised readily : - 4 c.c. of the blood in water 



compared with control similarly prepared. 



25 Equally well marked : 0*4 c.c. of blood in water compared with 



control similarly prepared. 



10 Difference from control quite noticeable. 



From these results it is clear that the quantities of carbon monoxide stated 

 by the French observers to be present in blood gases should be readily 

 recognisable by this method, for half the. amounts stated to be present in 

 normal blood are recognisable. 



In order to ascertain whether carbon monoxide was present in the blood of 

 anaesthetised animals the gases of cat's blood, never less and generally more 

 than 60 c.c. in volume, were evacuated from 108 c.c. or more of blood at 

 40° C, without the addition of any acid, until no further trace of gas could 

 be obtained. The chloroform used for ansesthetisation was chloroform puriss. 

 B.P. (made from acetone) washed with water, shaken with excess of anhydrous 

 potassium carbonate, filtered and then distilled. 



To quote some of the experiments : — 



Duration of Volume of very 



anuesthesia. dark blood, 



h. m. h. m. c.c. 



I. 12 52—2 19 54 



2 19—2 47 54 



The total gases were slowly bubbled through 1 :f00 fresh defibrinated cat's 

 blood and this examined against control solutions both diluted and undiluted. 

 The solutions were also examined with Michael's tintometer. No differences 

 whatever could be detected either by ourselves or by four separate 

 independent workers in the laboratory, all of whom were unacquainted with 

 the purpose for which the observations were being made. 



II. 191 c.c, of blood, from two cats deeply anaesthetised for 1 hour 6 mins. 

 and 1 hour 40 mins. respectively, were evacuated. The gas so obtained was 

 slowly bubbled through 1 : 100 blood solution and compared with control 

 blood solution through which an artificial blood gas containing chloroform 

 vapour was bubbled. No difference whatever in tint could be recognised 

 with the naked eye either in diluted or undiluted solutions by ourselves or by 

 five independent workers in the laboratory. This result was confirmed by 



