120 SUMMARY 01 CURRENT RESEARCHES RELATING TO 



usual way, and the celloidiu sections are treated as follows. They are 

 first mordanted with 4 p.c. iron-alum for 24 hours, and then rapidly 

 washed. Next they are stained with Weigert's hematoxylin (hfemato- 

 xylin 1 grm., alcohol 10 c.cm., water 90 c.cm., saturated solution of 

 lithium carbonate 2 c.cm.), for 24 hours : the staining at 37° in an 

 incubator is advisable, but not indispensable. After a wash in water 

 the sections are differentiated in two stages ; first with 4 p.c. iron-alum 

 until the grey substance begins to clear up, and then, after a careful 

 washing, in Weigert's solution (borax 2 p.c, ferricyanide of potassium 

 2*5 p.c). They are next washed in ammonia water, and after this 

 washed again in water for a long time : finally they are passed through 

 ascending alcohols to xylol and balsam. 



J. Nageotte * remarks that staining the celloidiu sections with 

 hfematein, and decolorizing with the ferricyanide solution, gives results 

 equally good. 



Staining the Medullary Sheath in Brain-sections.| — E. Potter 

 cuts sections of brain which have been fixed in 10 p.c. formalin, with the 

 Reichert large microtome. The sections, about 15 mm. thick, are then 

 placed in Weigert's fluorchrom-copper mordanting fluid for 14 days at 

 room temperature. They are then dehydrated in upgraded alcohols 

 (70°, 80°, 96°, 100°, 2 days each). Next ether-alcohol (aa) for 2 days, 

 as a preparatory for thin celloidin (2 days) ; this is followed by celloidin 

 of syrupy consistence. To render the thick celloidin more suitable for 

 sectioning it is advised to add 4 drops of cedar-wood oil to every 20 c.cm. 

 The celloidin is then allowed to inspissate, and when sufficiently thick- 

 ened the material is cut into blocks and preserved in 70 p.c. alcohol. 

 The sections are made with an immersion-microtome, and preserved, if 

 necessary, in 70 p.c. alcohol ; when required for staining they are placed 

 between two sheets of acid-free tissue paper. They are then immersed 

 in Weigert's iron stain without the hydrochloric acid for 2h to 3 hours. 

 On removal they are treated with Lustgarten's fluid, which makes the 

 cortex assume a dark-brown hue, the medullary sheaths being black. 

 After this the sections are further differentiated with borax 2, ferri- 

 cyanide of potash 2, H 2 100, until they assume a yellowish tinge. This 

 is followed by washing for several days in frequently changed water. 

 Then dehydration in upgraded alcohols, earbol-xylol, balsam. 



(5) Mounting-, including- Slides, Preservative Fluids, etc 



Method of Preserving Plague Material.^ — 0. Broquet finds that if 

 the viscera of animals affected with or dead of plague be preserved in 

 20 p.c. glycerin the virus will retain its activity for 8 or 9 days, while 

 the addition of 2 p.c. carbonate of lime gives still more satisfactory results. 



Bentley-Taylor Method of Mounting Mosquitos.§ — This method 

 is extremely simple and rapid. Twelve specimens can be mounted in 



* C.R Soc. Biol. Paris, pp. 517-19. 



t Zeitsckr. wiss. Mikrosk., xxvii. (1910) pp. 238-42 (1 fig.). 



t Ann. Inst. Pasteur, xxiv. (1910) pp. 888-94. 



§ Proc. Roy. Soc. Med., iv. (1910) med. sect., pp. 41-2. 



