32 NUTRITIVE QUALITY OF THE BLOOD. 



_. ^ ^ 



ditional quantities of blood are introduced into the vessels, lie 

 revives more and more, and soon breathes freely, moves with 

 facility, resumes his habitual gait and is completely re-established. 



32. This operation, known under the name of transfusion, is 

 certainly one of the most remarkable that has been performed, 

 and proves, better than all we could say, the importance of tne 

 action of the globules of the blood upon the living organs ; for if 

 we make use of serum, that is, blood deprived of its globules, in 

 the same manner, we produce no more effect than if we had used 

 pure water, and death is not a less inevitable consequence of the 

 haemorrhage. 



33. The influence of the blood upon the nutrition of the organs 

 may be demonstrated with equal facility. 



34. When by mechanical means we diminish, in an appreciable 

 and permanent degree, the quantity of this fluid received by an 

 organ, we perceive that it dwindles in size, and often even decays 

 and becomes reduced to almost nothing. 



35. On the other hand we observe, that the more any one part 

 of the body is exercised, the greater the quantity of blood it re 

 ceives, and the more it augments in volun.e. Indeed, every one 

 knows that muscular exercise tends most to the developement of 

 those parts which are the seat of it ; that in dancers for example, 

 the muscles of the legs, the calf in particular, acquire an extraor- 

 dinary size, while with bakers and other men who perform hard 

 labor with their arms, the superior members or extremities be- 

 come more fleshy than any other parts. Now, the muscles re- 

 ceive more blood when in action than when in repose, and by this 

 afflux of blood, the nutritive act of which they are the seat, is 

 stimulated and their volume is increased. 



36. The blood in giving nourishment to the organs, and in ex- 

 citing the vital movement, undergoes a change ; it is impoverished 

 not only by the deposite of the particles which the organs ap- 

 propriate to themselves, and incorporate with their substance, 

 but also by receiving the old materials which are separated from 

 the tissue of these same organs, and which, having become useless, 

 or even injurious, have to be expelled from the body. 



32. What is the operation of injecting blood into the veins called? Wha 

 iocs transfusion prove ? 



33. Does the blood influence the nutrition of the organs ? 



34 What is the effect of diminishing the quantity of blood received by 



an organ 



35. What effect does exercise produce on the different parts of the body ? 

 Why is the volume of the muscles increased when they are much exercised ? 

 3fi. Does the bLod undergo any change in nourishing the organs ? 



