414 Journal of Applied Microscopy. 



spleen. The liver cells lying between the occluded capillaries undergo necrosis 

 and disappear. The phagocytic cells themselves become necrotic, and fibrin 

 forms between them. Focal lesions due to phagocytic cells may occur also in 

 the kidney, heart, and testicle. The origin of the lesions in these three organs 

 is not yet definitely determined. 



The various processes are illustrated by eight colored plates, showing thirty- 

 four figures. r. m. p. 



Robertson, W. Ford. On a New Method of The tissue is placed in twenty times 

 Obtainine a Black Reaction in Certain . , , _ ^ ,. 



Tissue Elements in tlie Central Nervous ^^S volume of a per cent, formalin 

 System (Platinum Method). Scottish Med. solution with 1 per cent, platinum 

 and Surg. Jour. 4: i, i8qo. , , . , ™, , , • , , , , 



chloride. 1 he bottle is loosely corked 



and the tissue is allowed to remain in the fluid for several weeks after the tissue 

 begins to blacken, which it generally does in one to three months. If the plati- 

 num chloride becomes exhausted before blackening is marked, more can be 

 added. Sections are cut with the freezing microtome and mounted as in other 

 impregnation methods. 



The platinum chloride picks out and blackens certain elements, among which 

 are long branching and anastomosing fibers in the walls of the blood vessels 

 (arteries, capillaries, arterioles, and venules) of the cord and brain. Robertson 

 believes these to be the connective tissue fibers of the adventitia. 



When the reduction process is more marked the primitive fibrils of the nerve 

 cells are darkened. The Nissl bodies cannot be seen. Around the nucleus of 

 a nerve cell the primitive fibrils can be seen forming a network, and it is from 

 this network of fibrils that the axis cylinder is formed. In the nucleus of the 

 large nerve cells are seen six to twelve large blackened particles, evidently the 

 acidophilic particles. 



In the brain of the dog were found, in both cortex and medullary substance, 

 numerous small branching cells with a round nucleus and a small amount of 

 granular protoplasm. The nucleus is about the size of a red blood corpuscle ; 

 the processes are three to six in number. These do not appear to have any 

 relation to other histological elements of the brain. Similar cells were seen in 

 the one human brain examined by this method. Robertson thinks that these 

 cells form a special tissue element of the nervous system not previously recog- 

 nized as such. R. M. p. 



Kronlhal, P. Eine neue Farbung fiir das This stain for the ganglion cells and 

 Nervensystem Neurologisches Central- ,-, , , , 



Watt. March i, 1899. fibers of the central nervous system 



depends on the precipitation of lead 



salts. Pieces of tissue are placed in equal parts of a 10 per cent, formalin 



solution and a saturated solution of lead formate for five days, and then in equal 



parts of 10 per cent, formalin and a saturated solution of hydrogen sulphite for 



five days, after which they are placed in alcohol until imbedded. All the cells 



and the fibers, to their finest ramifications, are sharply impregnated. 



R. M. p. 



