NEW CONCEPTIONS IN SCIENCE 



fessor Golgi found that the inner substance of the 

 nerves, the nervous substance par excellence, was 

 very greedy of certain salts of silver, so that if a 

 piece of brain or a nerve be soaked in a solution 

 of these salts, the inner parts are stained a vivid 

 black. 



The revelations of this simple method, since ex- 

 tended in various ways, have been of extraordinary 

 interest. Speaking broadly, a nerve resembles noth- 

 ing so much as a vigorous tree, with a big tap root 

 and a short, fat trunk, and crowned with a wonder- 

 ful arborescence. And if you take a bit of brain 

 and soak it in the staining solution, then harden it, 

 cut it into extremely thin slices, say a few hun- 

 dredths of an inch thick, and put this thin bit under 

 a powerful microscope, the picture you get is like a 

 cross-section of an immense forest. The trees are 

 crowded together, and roots and the myriad branch- 

 es interlace in apparently inextricable confusion. 



Yet as the methods grew more and more delicate, 

 so that microscopes of greater power could be used, 

 it was seen that this confusion is only apparent. 

 The nerves do branch in a bewildering way, but 

 there seems plenty of room, and just now the pa- 

 tient, persevering students of brain anatomy are 

 divided into two warring camps over the question 

 as to whether the nerves ever touch one another at 

 all. 



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