410 



INFLAMMA TION. 



the corpus striatum, thalamus options, the cortex of the left hemisphere, also 

 the white substance of the same, which, as is evident from the history, was 

 the seat of the abscess. The specimens thus obtained were stained, partly 

 with an ammoniacal solution of carmine, partly, after thorough washing out 

 with distilled water, with a one-half per cent, solution of chloride of gold. The 

 different sections were mounted in glycerine, diluted with distilled water this 

 method of mounting, as experience teaches, being far superior to the method 

 of mounting in Canada balsam or dammar varnish. While glycerine-mounted 

 specimens, if taken from properly hardened material, keep almost any length 

 of time, never losing their sharp and definite outlines of detail, Canada balsam 

 specimens, on the contrary, very soon become so transparent that their 

 minute details are completely lost to sight, and only the coarser formations 

 remain distinguishable. Canada balsam specimens, therefore, are fit for 

 lower powers of the microscope only; they are worthless for a power 

 exceeding 400 diameters, or for any power intended to give a display of the 



m-M 



FIG. 172. WALL OF AN ABSCESS OF THE BRAIN. 

 TRANSVERSE SECTION. 



F, layer of fibrous connective tissue with scanty blood-vessels, bounding the abscess ; M, 

 layer of myxomatous connective tissue, with numerous capillary blood-vessels ; W, white 

 substance of the brain, with numerous large blood-vessels. Magnified 200 diameters. 



more minute anatomical features. Our lack of knowledge of the minute 

 pathological anatomy of the central nervous organization is mainly due to the 

 method of mounting in Canada balsam. 



The subject of these investigations will be treated under the four follow- 

 ing heads, namely : Inflammatory changes of 



(1) Wall of abscess; (2) white substance; (3) non-medullated nerve- 

 fibers ; (4) gray substance. 



(1) Wall of Abscess. Transverse sections through the wall of the abscess, 

 which in different places varied in width from one to two millimeters, exhib- 



