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



The general arrangement of the apparatus is shown in the accompanying- 

 figure. The oxygen current passes from left to right through (1) combustion 

 tube, (2) bulbs containing 40 per cent, potash, (3) bulb containing the gas 

 under examination, (4) a U-tube containing powdered potash, the proximal 

 limb of which was slightly moistened, (5) a calcium chloride drying tube, 

 (6) tube containing iodic anhydride, (7) absorption vessel containing 10 c.c. 

 of a 10 per cent, potassium iodide solution to absorb any liberated iodine 

 (this was kept cool during the experiment), and (8) aspirator. 



1 2 34567 8 



The bulb (3) was either one of Waller's densimeter bulbs of 255 c.c. 

 capacity for mixtures of chloroform and air, or, in the case of blood gases, 

 a 200 c.c. tube with stopcocks at either end. 



Effect of Heat on Iodine Pentoxide. 



Dr. Wade, of Guy's Hospital, who has for some time past been engaged in 

 studying the methods of estimation of small quantities of carbon monoxide, 

 kindly informed us, when we commenced these experiments, of the fact which 

 he had observed that iodine pentoxide invariably gave off iodine when first 

 heated, and that this evolution of iodine never actually ceased, although the 

 rate eventually became steady if the temperature was maintained constant. 

 This we can entirely confirm. We used iodine pentoxide tubes of a special 

 kind devised by Dr. Wade, a full description of which, along with his results, 

 he is about to publish. For this reason we give no further account of our 

 experiments in this direction. 



Effect of Chloroform Vapour on Iodine Pentoxide at various Temperatures. 

 The above-mentioned tubes were thoroughly cleaned and filled with 28 to 

 30 grammes of powdered iodine pentoxide and heated for a short time in 

 aniline vapour, but in no case was any considerable quantity of water vapour 

 evolved. The oxide was then heated in a current of purified oxygen for 24 to 

 48 hours or longer, the tube being placed in the vapour of a suitable liquid, 

 boiling at the temperature we desired to use in an actual experiment, until the 



