158 THE CIRCULATION 



possible by it to cure all forms of disease," and even to make 

 the old young again. But these claims were soon found to be 

 extravagant, and many unhappy accidents occurred in its prac- 

 tice; so that being forbidden by government and interdicted 

 by the Pope, it rapidly fell into disuse. At the present time, 

 however, it is sometimes resorted to in extreme cases, when 

 there has been a great and rapid loss of blood ; and there are 

 upon record several instances where, other means having 

 failed, life has been restored or prolonged by the operation of 

 transfusion. 



17. This reviving power of the blood seems to reside in the 

 corpuscles; for transfusion, when performed with the serum 

 alone, has, in every case, proved fruitless. Now, though so 

 much depends upon the blood and its corpuscles, it is a mis- 

 take to suppose that in them alone is the seat of life, or that 

 they are, in an exclusive manner, alive. All the organs and 

 parts of the body are mutually dependent one upon the other, 

 and the complete usefulness of any part results from the har- 

 monious action of the whole. 



18. Change of Color. The blood undergoes a variety of 

 changes in its journey through the system. As it visits the 

 different organs it both gives out and takes up materials. In 

 one place it is enriched, in another it is impoverished. By 

 reason of these alterations in its composition, the blood alsd 

 changes its color. In one part of the body it is bright red, or 

 arterial ; in another it is dark blue, or venous. In the former 

 case it is pure, and fit for the support of the tissues ; in the 

 latter, it is impure and charged with effete materials. (The 

 details of the change from dark to bright will be given in the 

 chapter on Respiration.) (Read Notes 4, 5, and 6.) 



the blood flowing through the canals of our organization carries nutriment 

 to all tissues, and refuse from them." darkens Sex in Education. 



4. On Purifying the Blood. " By some the blood is regarded as the 

 source of all diseases, and to 'purify the blood' is the object of their 

 treatment. Quacks seize on this notion, and in sublime ignorance of the 



17. The seat of the reviving power of the blood ? What further is related ? 



18. Changes in the blood ? What further is stated ? 



