114 SUMMARY OF CURRENT RESEARCHES RELATING TO 



2 p.c. chromic acid or of 5 p.c. potassium bichromate is added. The 

 solution is heated to boiling, and when cold filtered. The residue is 

 dried in an incubator at 30°, and then dissolved in 90 p.c. alcohol (100 

 parts). After acidulatiou with 1 p.c. HC1 it is filtered. The sections 

 are immersed for two hours and then transferred to 90 p.c. alcohol fox- 

 half an hour. The elastic tissue is stained a dark violet. 



Neutral Red for Staining Nucleated Red Blood-Corpuscles. * — 

 Dr. Bettmann has found neutral red a most satisfactory reagent for de- 

 monstrating the presence of nucleated erythrocytes. The technique is 

 simple. It is sufficient to mix with a drop of blood some saturated solu- 

 tion of neutral red, or to add a granule of the solid pigment. But by 

 adopting Arudd's elderpith method (see this Journal, 1897, p. 81) still 

 better results were obtained. The nuclei of the erythroblasts show up 

 as dark brownish-red masses surrounded by the pale brown cell-body. 



Demonstrating the Seminal Tubules of the Rat by means of 

 Renaut's Fluid.f — C. O. Regaud demonstrates the membrane of the 

 seminal tubules of the rat by injecting Renaut's fluid into the testicle. 

 The fluid consists of saturated aqueous solution of picric acid 80 vols., 

 1 p.c. osmic acid 20 vols. ; to 3 vols, of this mixture 1 vol. of 1 p.c. 

 nitrate of silver solution. 



New Method for Staining en masse.} — A. Spuler describes a method 

 for staining pieces which has tho advantages of imparting a regular 

 staining to each section, and of affording excellent preparations for 

 demonstration with the projection-apparatus. The fixed pieces are 

 treated with cochineal solution prepared by boiling finely powdered 

 cochineal in distilled water, filtering, and evaporating down almost to 

 dryness. Distilled water is again added and the mixture filtered. In 

 this solution the pieces are left for 24 hours or more on the top of a 

 paraffin oven. After having been washed they are mordanted in a thin 

 solution of iron-alum. This converts the red colour to black. The 

 mordanting over, the pieces are thoroughly washed with distilled water 

 and then imbedded in the usual way. 



New Method for Staining Nervous Tissue. § — Dr. T. Kodis has 

 devised the following procedure, in which hematoxylin molybdate is 

 the effective ingredient : — Pieces of fresh tissue i-1 cm. thick are 

 placed in saturated aqueous solution of mercury cyanide for 1-2 days, 

 or longer. They are then put straight away without washing into 

 10 p.c. formalin for 1-3 days. Sections are made by a freezing micro- 

 tome, and stained for 1-2 minutes in much-diluted solution of the 

 hematoxylin molybdate (hematoxylin crystals 1 ; molybdic anhydride 

 1*5 ; aq. destill. 100 ; H 2 0., 0*5, or a crystal of HgO : the solution is 

 ready for use in a few days). The stained sections are washed for 1-2 

 minutes in water, and having been contrast-stained with alcoholic solu- 

 tion of Lichtgrun, are mounted in balsam. 



* Zeitschr. f. angew. Mikr., vii. (19(11) pp. 177-S2. 

 t Arch. Anat. Microscop., iv. (1901) pp. 101-53 (2 pis.). 



X Deutsch. Med. Wochenschr., xxvii. (1901) No. 14, Yemnsbeilage, p. 116. Se3 

 Zeitsch f. wiss. Mikr., xviii. (1901) pp. 1S3-4. 



§ Arch. f. Mikr. Anat. u. Kntwickl., lix. (1901) pp. 211-20 (1 pi.). 



