696 SUMMARY OF CURRENT RESEARCHES RELATING TO 



hear from others their experience on the matter, not alone in human 

 tissues but in those of the lower animals. 



My present belief is, that if nervous tissues are placed at once in 

 spirit they will sooner or later show the presence of bodies which do 

 not stain with carmine or logwood, and which, in some cases, do stain 

 with osmic acid. These bodies are not all alike ; some have a very 

 suspicious foreign appearance, but others are so like some degene- 

 rations that they have been described as such. Some are of irregular 

 rounded outline of varying size ; some do take staining in a faint 

 way, and some have a semi-crystalline look which confirms one's idea 

 that they are not antemortem, but the result of the process of prepa- 

 ration. What I should specially like to know is if others have met 

 them in similar conditions. Spitka of America described such bodies, 

 and I have heard — but have not the references — that certain German 

 writers recognize them as artificial. 



In describing my experiences, I would say that they appear in 

 nervous tissues when these have been in spirit for not less than two 

 months, and that they are more common in the white matter, at all 

 events at first ; the more crystalline bodies, in my experience, do not 

 occur till later. I believe that some of the non-staining bodies are 

 due to a breaking up of the white matter of Schwann, Again, I believe 

 that if the specimens are placed in spirit without being finely divided 

 before hardening, they are more liable to produce these bodies. I shall 

 be happy to provide any one with specimens if they will further 

 investigate the matter." 



Hailes' Poly-microtome. — Dr. Hailes sends us the following direc- 

 tions for using this instrument, which was described at p. 1036 of 

 vol. iii. : — 



When the microtome is used for freezing, remove the glass table, 

 and cover the ice-jacket with felt or gutta-percha, to prevent absorp- 

 tion of heat from the atmosphere. Oil the screw and plunger, to 

 prevent them becoming fixed by the freezing (too much oil interferes 

 with freezing) ; screw the cylinder into position on the bed-plate. 

 Enclose the top with a tightly fitting cork, to prevent the entrance of 

 ice, &c. Put on the hopper cover, and fill the ice-jacket with very 

 finely powdered ice and coarse salt, through the hopper, and stir 

 the contents by rotating the hopper cover. In a few moments the 

 cylinder will be cooled down to freezing-point. Remove the hopper 

 lid, and cork and fill the cylinder two-thirds full with mucilage 

 acacia, British pharm. ; then replace the cork and hopper lid, and 

 stir for a few moments. 



When a white frozen film has formed at the periphery, then intro- 

 duce the previously prepared specimen into tbe mucilage in the well 

 of the microtome, holding it against the advancing film of ice until it 

 becomes fixed in the desired position ; then pour in a little more 

 mucilage so as to cover it completely, recork the cylinder and re- 

 place the hopper lid, and stir, adding ice and salt as it becomes 

 necessary, until the specimen is solidly frozen. 



When perfectly frozen, exchange the hopper lid for the glass table, 

 which has previously been cooled by contact with ice, then cut in the 



