140 REroRT — 1871. 



which tho hlood there undergoes. Of the nature of those changes, little or 

 nothing is known," 



In my early researches, conducted during the months of May and June 

 1869, I had attempted to determine, by means of comparatively simple con- 

 trivances, whether any heat was evolved during arteriahzation, making use of 

 delicate thermometers. At first I used a glass bottle furnished with a tubu- 

 lature, near the bottom in which a cork, perforated and furnished with a glass^ 

 tube closed by india-rubber tubing and a clip, was inserted. The neck of the 

 bottle was furnished with a cork perforated in two places ; through one of 

 the perforations a delicate Centigrade thermometer passed into the centre of 

 the flask, whilst into the other was inserted a bent glass tube through which 

 gas might be introduced into the apparatus. The bottle which I have de- 

 scribed was filled with venous blood, both the tubes communicating with its 

 interior being closed. It was then maintained at a temperature varying be- 

 tween 30° and 35° C. for many hours, until it had assumed the characteristic 

 cherry-red coloration which indicates the complete removal of the loosely 

 combined oxygen of the blood. The apparatus having been allowed to cool, 

 it was invested with a jacket of felt. An india-rubber tube was made to 

 connect the upper glass tube with a hydrogen gasometer, whilst the lower 

 tube being opened, the hydrogen expelled any required quantity of blood. 

 The apparatus was then shaken and the temperature determined. Then by 

 a repetition of the process (followed in the introduction of hydrogen) pure 

 oxygen gas was made to displace more of the blood, and the process of shaking 

 repeated as before. The results of such experiments were eminently unsatis- 

 factory, varying obviously with the amount of mechanical work which was 

 formed by the experiments, and which yet did not admit of exact deter- 

 mination. 



In some experiments I observed a heating which amounted to 0°-3 C. ; in 

 other cases the difference in the readings, before the introduction of oxj^geu 

 and after it, seemed to point to a cooling instead of to a heating. To 

 give an idea of the indefinite and perplexing results which I obtained, I 

 shall cite the details of an experiment performed on the 23rd of June, 1870, 

 by Professor Tait and myself, the apparatus used being a tin vessel resem- 

 bling in principle the one of glass which I have already described. This 

 vessel was covered with felt, and, when shaken, it was held by means of a 

 very strong iron clamp. Having been filled with sheep's blood, it was placed 

 in an air-oven and maintained for a period of twelve hours at a temperature 

 which oscillated between 100^ and 110° Pahr. It was afterwards placed in 

 the room in which my experiments were carried on ; but in order to make 

 it cool more rapidly, its felt covering was taken off, and it was placed in 

 water at a temperature of 15° C. It was dried, again covered with felt, 

 and fixed in its clamp. Hydrogen was then made to expel 4-5 cubic 

 inches of blood, which was found by spectroscopic examination to exhibit the 

 single band of reduced haemoglobin ; after shaking the blood and hydrogen 

 in the apparatus, its temperature was found to be 17°'S 0., then 18° C, the 

 temperature of the air being 20°-4 C. 10 cubic inches of blood were then 

 drawn off and replaced by oxygen, which was brought in contact with the 

 blood by shaking ; the temperature rose to 18°-1 C. : more oxygen was intro- 

 duced and the shakinc; repeated, the temperature rising to 18°-25, 18°-4, 18°-5, 

 18°-6, 18°-6, 18°-55,l8°-7, 18°- 75, 18°-77. At the conclusion of the experi- 

 ment the quantity of blood which had been arterialized was found to be 3G0 

 cubic centims. This experiment merely gave one of many results ; for as long 

 as I followed this method I was quite unable twice to determine the same 



