ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 305 



at the proper angle to the blade of the knife, regulated by means of the 

 finely cut screw-thread of the table. 



The knife is curved, about five inches in length, and about one inch 

 in breadth, ground flat on the under side, and held in position by a 

 binding screw after the fashion of several microtomes now in use. A 

 straight knife may be used if desired. 



Substitute for Corks in Imbedding.* — Dr. G. C. Freeborn suggests 

 as a substitute for corks, cylinders of white pine, one inch high, and 

 varying in diameter from half to one and a half inches. These " deck 

 plugs " offer the same advantages as corks for celluidin imbedding, but 

 do not, like corks, get soft in spirit. 



HuBEECHT. — Demonstration des De Groot'schen Mikrotomes. (Demonstration of 

 the De Groot microtome.) 



A7iat. Anzeig., III. (1888) p. 722. 



( Verh. Anai. Gesell. Wilrzburg.) 



"Microtomes ad infinitum have been invented within the past few years for the 



purpose of more elFectually slicing into infinitesimal and well-nigh invisible 



sections the ' harmless, necessary cat,' and other animals. This may be called 



the microtome era of microscopy — microtomes rival camera-lucidas in multitude." 



Queen's Micr. Bulletin, V. (1888) p 32. 

 ScHiEFFEEDECKEE, P. — Mittheilungen von den Ausstellungen wissenschaftlicher 

 Apparate anf der Anatomen-Versammlung zu Wiirzburg und der 61. Versammlung 

 deutscher Naturforscher und Aerzte in Kciln im Jahre 1888. (Notes on the 

 Exhibitions of Scientific Apparatus at the Anatomists' Meeting at Wiirzburg, and 

 tlie 61st Meeting of German Naturalists and Physicians at Cologne in 1888.) 

 [Contains especially notes on the various microtomes at the exhibitions.] 



ZeUschr.f. Wiss. Mikr., V. (1888) pp. 471-81 (2 figs,). 



(4) Staining and Injecting'. 



Carminic Acid Stain.f — Dr. G. C. Freeborn recommends Dim- 

 mock's solution for histological work. This is a 3/4 per cent, solution 

 of carminic acid in 85 per cent, alcohol. The sections are stained in 

 two to five minutes. If a pure nuclear stain be required, wash in 1 per 

 cent, hydrochloric acid. The solution stains ganglion-cells very well if 

 used in the following manner : sections of central nervous system are 

 overstained in Dimmock's solution, and then washed in a 10 per cent, 

 aqueous or alcoholic solution of the officinal solution of the chloride of 

 iron. Herein the colour of the sections changes from red to black, and 

 as soon as the hue alters to yellow, the section is washed thoroughly in 

 water, dehydrated, cleared in origanum oil, and mounted in balsam. 



By this process the nerve-cells and their processes are stained black, 

 the intercellular substance being yellowish. 



Staining Connective Tissue with Nigrosin (Indulin, Anilin Blue- 

 black). J — Dr. G. C Freeborn recommends nigrosin for staining con- 

 nective tissue. The solution used is made by mixing 5 ccm. of a 1 per 

 cent, aqueous solution of nigrosin with 45 ccm. of an aqueous solution 

 of picric acid. This makes a dark olive-green fluid. Sections are 

 placed in this solution for three to five minutes, and then washed in 

 water until their colour changes from a yellowish-green to a deep blue. 

 The sections are then dehydrated, cleared in oil of cloves, and mounted in 

 balsam. 



After dehydration the sections may be double stained for five or six 



* Amer. Men. Micr. Journ., ix. (1888) p. 232. t Ibid., p. 231. 



X Ibid., p. 231. 



