1090 SUMMARY OF CURRENT RESEARCHES RELATING TO 



best is Grenadier's hematoxylin. After having been stained the 

 sections are carefully washed and mounted in glycerin or some watery 

 medium. 



If it be desired to mount in a resin, the slido is placed in 95 per 

 cent, alcohol for 15 minutes, the section is then dried as quickly as 

 possible, and some drops of origanum oil passed over it. The sections 

 clear in five minutes and then some more origanum oil is applied, or 

 better, some xylol, and theso having been displaced, the sections are 

 mounted in resin. 



Ehrlich's Hematoxylin Solution.* — Prof. P. Ehrlich gives the 

 formula for tho hematoxylin solution invented by him : — H 2 0, 

 100 c.cm. ; absoluto alcohol, 100 c.cm. ; glycerin, 100 c.cm. ; acetic 

 acid, 10 c.cm. ; hematoxylin, 2 grm. ; alum in excess. The mixturo 

 is exposed to light until it assumes a deep red colour. The staining 

 power is retained for years. No precipitate ever occurs, provided tho 

 vessel is properly corked. If need be, the solution may be employed 

 for double staining. 



The author omits to state that sections stained with this pre- 

 paration should be placed in ordinary (tap) water which is slightly 

 alkaline, not IPO, in order to bring out the blue colour. 



New Staining Method for the Central Nervous System.t — Herr 

 C. Benda hardens small pieces of fresh material in cold saturated 

 picric acid. Hardening is usually completed in two or three days, 

 but longer immersion in the picric acid is not at all harmful. When 

 thus soaked the preparations are hardened again iu alcohol. Celloidin 

 appears to have an unfavourable influence on the sections, and paraffin 

 is to be preferred as a saturative medium. Sections, made as thin as 

 possible, are placed for some hours in a solution of an iron salt (the 

 author employed a concentrated solution of iron sulphate), and these 

 after careful and repeated washing in water are transferred to a 1 per 

 cent, watery solution of hematoxylin until they become a deep black 

 colour (about 10 minutes). They are next bleached for about five 

 minutes in chromic acid (1 to 2000), washed well in water, dehy- 

 drated, and mounted in balsam. This method is stated to give results 

 equal to those of the best carmine and nigrosin stainings ; not only 

 are the coarser fibres and their communications with the ganglion 

 cells clearly shown, but the intimate structure of the ganglion cells 

 themselves is made evident. 



Action of Methyl-blue on Living Nervous-tissue, f — Dr. P. 

 Ehrlich has, since his experiments with alizarin blue, investigated tho 

 action of methyl-blue on living nervous matter. This staining 

 substance was found to possess an extraordinary affinity for the axis- 

 cylinders, even to the finest ramifications of nerves in the larynx, the 

 eye, and the diaphragm, but not in other parts of the body. Satura- 

 tion with oxygen and an alkaline reaction of the fibres are the two 

 conditions on which this reaction is dependent. 



* Zeitschr. f. Wiss. Mikr., iii. (1886) p. 150. 



t Arch. f. Anat. u. Physiol. (Physiol. Abth.), 1886, pp. 562-4. 



% Deutsch. Med. Wochenschr., 1886, No. 4. 



