i IS Progress of Foreign Science. 



fied that it is impossible to draw from them general conclusions 

 relatively to the composition of the serum. This liquid varies in 

 the same animal, and also from one animal to another, without its 

 being possible to connect this character with the physiological con- 

 dition of the individual. But this is not the case with the par- 

 ticles. In the greater number of cases, their quantity exhibits a 

 certain relation to the heat developed by the vital action. The fol- 

 lowing table renders this position pretty evident. In it are assem- 

 bled the weights of the particles iu one thousand parts of blood, 

 the habitual temperature of the rectum, the number of pulsations 

 of the heart in a minute, and the number of inspirations in the 

 same time. To complete our knowledge on this subject, the ratio 

 of the total weight of the blood in circulation to the weight of the 

 animal is wanting. MM. Prevost and Dumas are now engaged 

 in this difficult, and hitherto inaccurate, estimate, but one, indispen- 

 sable to the application of the facts here detailed. 



By drawing only a little blood from a large animal, these gentle- 

 men tried to determine the relative natures of arterial and venous 

 blood. The results on a sheep were as follows : — 



