PROBLEMS OF MODERN SCIENCE 



insurmountable, but quite recently an entirely new 

 way of attacking the problem has been opened 

 up by the experiments of two American workers, 

 Messrs Guyer and Smith. These ingenious in- 

 vestigators base their operations upon our recently 

 acquired knowledge of the marvellous properties 

 of the blood in its reactions against the intrusion 

 of foreign albuminoids. The study of the blood 

 from this point of view has developed almost into 

 a new science, which perhaps might have been 

 included in our schedule as a separate category, 

 but which is really a part of Biochemistry and 

 Biophysics. Thus the injection into the blood- 

 stream of the red corpuscles, or of the spermatozoa, 

 of a distinct species of animal causes the appearance 

 in the blood of an ' antibody ' or ' lysin ' which 

 has the property of dissolving and destroying the 

 foreign substance. The modern theory and prac- 

 tice of immunisation depend primarily upon this 

 remarkable reaction. 



Guyer and Smith, by injecting an emulsion 

 composed of the lenses of rabbits' eyes pounded 

 up in normal salt solution into the blood of fowls, 

 produced a ' lens-sensitised ' serum capable of 

 dissolving the lens-substance. This serum was 

 then injected into the blood of pregnant rabbits, 

 and it was found that the young animals were 

 born with defective lenses. The result, so far, 

 was of course merely the appearance of a bodily 

 140 



