112 SUMMARY OF CURRENT RESEARCHES RELATING TO 



from shaking the bottles. When it is necessary to remove the stoppers 

 this should be done in a closed gas-chamber. 



Paraffin Imbedding in Vacuo. * — Dr. R. Kolster uses chloroform 

 xylol or toluol as solvents, and after saturating the pieces in the usual 

 way places them under the air-pump and exhausts the air. In the vacuum 

 the last traces of the volatile solvent or of air are removed and a solid 

 homogeneous block remains. 



Saw for making Microscopic Preparations of Hard Objects.f — 

 G. Arndt has devised a saw for making microscopical sections of hard 

 objects. It is on the lines of a fret-saw but having two parallel blades 

 which arc kept in a state of tension and prevented from sagging by 

 clamping screws. The results obtained from its use are satisfactory. 



(4) Staining- and Injecting-. 



Preparation of Pure Pvomanowsky-Nocht Stain. J — Dr. K. Reuter 

 prepares eosin- methyl en-blue by heating for three days in an incubator 

 at from 50°-60° C. 0*5 Na 2 C0 3 and 100 ccm. 1 p.c. aqueous solu- 

 tion of medicinal methylen-blue Hochst, and after filtering, adding 

 saturated aqueous eosin solution. The precipitate which comes down is 

 washed with distilled water and, having been dried, is dissolved in a 

 water-bath in hot absolute alcohol. The solution is filtered, and to every 

 100 ccm. 2 ccm. of anilin oil are added. The results obtained by 

 staining malaria blood-films are said to be very striking. It is best to 

 keep the pigment dry and make a stock solution from time to time. 

 Then about 0-2 grm. is dissolved in 100 ccm. C 2 H ti O by the aid of heat 

 and 2 ccm. of anilin oil added. Of this st'>ck solution 30 drops are 

 added to about 20 ccm. of distilled water. The preparations are stained 

 for a half to several hours, and to obtain a good effect the films should 

 be protected against aqueous moisture. Attention is drawn to the fact 

 that the solution is alkaline. 



Kresylecht Violet.§ — R. L. Morse recommends kresylecht violet for 

 general staining purposes, and prepares the solution by mixing together 

 •5 p.c. aqueous solution of phenol 80 cc. and 95 p.c. ethyl alcohol 20 cc, 

 and then adding 1 grm. of the pigment. After all the stain is dissolved 

 the solution is filtered. Stain for 1-5 minutes. Wash in distilled 

 water. Mop up. Anilin-xylol (2-1). Pure xylol balsam. 



Very good results are obtained with Gonococcus, mucin, amyloid, 

 plasma-cells, and cancer bodies. 



New Fat-staining Pigment. || — Dr. L. Michaelis recommends a scar- 

 let or poppy-i*ed pigment for staining fat. The chemical name of the 

 new dye is Azo-orthotuloazo /?-naphthol ; its trade name Scharlach R, 

 or Fettponceau. The pigment is insoluble in water, soluble with diffi- 

 culty in alcohol, but easily soluble in chloroform, oils, and melted 

 paraffin. It is soluble in strong H 2 S0 4 , the solution being blue ; all 

 other solutions are red. A saturated solution of Scarlet R in 60-70 p.c. 



* Zeitscbr. f. wiss. Mikr., xviii. (1901) pp. 170-3. 



t Tom. cit, pp. 146-59 (9 figs.). 



t Centralbl. Bakt., 1" Abt., xxx. (1901) pp. 248-oG (2 pis.).' 



§ Journ. Applied Microscopy, iv. (1901) pp. ' 



|| Vircbow's Archiv., olxiv. (1901) pp. 263-'3 



1492-4. 



-70. 



