896 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Staining black the processes from Ganglion-cells.* — Dr. C. 

 Golgi's method is said to give very excellent results. 



Pieces of cerebellum or medulla from 1 to H cm. in size are 

 hardened in a 2 per cent, bichromate of potash solution. The strength 

 of this may afterwards be increased to 3 per cent. Six or eight days 

 suffice (but it is better to wait twenty to thirty days) to obtain the 

 necessary hardness, the bichromate solution being frequently changed. 

 The pieces are then placed in • 5 or • 25 to 1 per cent, solution of 

 porchloride of mercury, wherein they may remain for at least two 

 months. 



The author further describes successive staining with potassium 

 bichromate or ammonium bichromate and 0*75 per cent, silver nitrate 

 solution, or with a mixture of 8 parts 2-2 ' 5 per cent, bichromate, and 

 2 parts 1 per cent, hyperosmic acid. 



Bizzozero's Picrocarmine.'f — Dr. G. Martinotti desires to correct 

 the words in the original notice J (heated in a water-bath) " until one 

 no longer perceives even the slightest ammoniacal odour," for " until a 

 slight but evident ammoniacal odour is perceived." 



Methyl-blue. § — Dr. P. Ehrlich, in order to determine the re- 

 ceptivity of animal tissue for oxygen, injected into the veins of 

 rabbits large quantities of a dilute solution of methyl-blue, and 

 found that as with alizarin, the majority of the organs showed more 

 or less strong primary staining, while in some, such as the liver and 

 lungs, the pigment became changed by oxidation to white. Methyl- 

 blue takes a place about half-way between ; alizarin and indophenol 

 being more easily reducible than the latter, and with rather more 

 difficulty than the former. Post-mortem reduction takes place extra- 

 ordinarily quickly, perhaps as rapidly as with indophenol, and it is 

 therefore advisable to inspect the organs as soon as possible, even 

 while the animal is alive. 



Anilin-blue-black.|| — Dr. G. Jelgersma in defending anilin-blue- 

 black from the attacks recently made upon it, recommends the 

 English-made dye, from which he has always obtained most satisfactory 

 results. 



1. The preparations are permanent; specimens exposed to full 

 daylight for over a year have not deteriorated. 



2. Anilin-blue-black is specially adapted for nervous tissue, axis- 

 cylinders, ganglion-cells and their processes. In preparations of the 

 cortex cerebri et cerebelli, Purkinje's cells, with their processes, are 

 seen branching as far as the periphery. Pathological changes in the 

 ganglion-cells are most easily observed in this stain. The axis- 

 cylinders become dark-blue and easiest recognized in vertical section, 

 although in oblique and parallel directions they are very clear. 



* Cf. Virchow and Hirseh's Jahresber. Anat. u. Physiol, for 18S5 (1886) p. 38. 

 t Zeitschr. f. Wiss. Mikr., iii. (1886) p. 57. 



X Ibid., ii. (1885) p. 539. See this Journal, ante, p. 350, where the words are, 

 " until every trace of ammonia has disappeared." 

 § Centralbl. f. d. Med. Wiss., 1885. pp. 113-7. 

 || Zeitschr. f. Wiss. Mikr., iii. (1886) pp. 39-40. 



