314 SUMMARY OF CURKENT RESEARCHES RELATING TO 



fixative chiefly used was Fleniining's fluid. Small pieces of tissue were 

 immersed for one to two days, and after a careful washing in water were 

 dehydrated in alcohols of increasing strength. They were then embedded 

 in celloidin. The sections were stained in an acid solution of orcein. 

 After a stay in the staining solution for twenty-four hours, the sections 

 were decolorized for five minutes in 96 p.c. acid-alcohol. Novikoff's 

 method was also used. This stain consists of O'Ol p.c. solution of 

 triphenylrosanilnitrisulphate of sodium in saturated aqueous solution of 

 picric acid. In this fluid the preparations remain for twenty -four hours, 

 and then are differentiated in 45 to 50 p.c. alcohol. In these preparations 

 the elastic fibres are yellow, connective-tissue blue, and muscle green. 

 Another method tried was staining the celloidin sections with safranin 

 or twenty-four hours, and then washing in water followed by weak 

 alcohol, afterwards transferring to orcein solution for G hours, and finally 

 differentiating in acid-alcohol or in picric acid. 



Fixation was done with Muller's fluid, with or without addition of 

 formalin, but the resulting pictures were not so clear or distinct. 



Staining Spirochaeta pallida.* — According to C. Birt, the most 

 effective way of staining Spirochaeta pallida is as follows : — The films are 

 first air-dried and then fixed in a fluid composed of acetic acid, 1 c.cm. ; 

 formalin, 20 c.cm. ; distilled water, 100 c.cm. This must be renewed 

 several times in the course of a minute. After washing in water the 

 films are mordanted with 5 p.c. tannic acid in 1 p.c. carbolic acid. The 

 slide covered with mordant is heated to vaporization, and after half a 

 minute is washed with water. While still moist the film is stained with 

 " 25 p.c. silver nitrate in distilled water, to which a minute trace of 

 ammonia is added until slight turbidity occurs. The film covered with 

 stain is heated to vaporization and left for half a minute. It is then 

 washed, dried, and mounted in xylol-balsam. The spirochastes are jet 

 black, and appear to be much thicker than when stained with anilin 

 dyes. 



Morphology of the Eye-muscle Nerves.j — In the course of the 

 present study H. V. Neal used different methods. Among those 

 which have given the best results are Cajal's nitrate of silver, Paton's 

 modification of Bielschowsky's method, Held's molybdic acid-hemat- 

 oxlin stain and vom Rath's picro-acetic-osmic-platinic chloride-pyro- 

 gallic acid treatment. The Vom Rath ('95) method is as follows : — 



1. Fix in the dark for one to three days in the following mixture 

 (use plenty and change each day) : Saturated and filtered solution picric 

 acid, 200 c.cm. ; glacial acetic acid, 2 c.cm. ; Platinic chloride (dissolve 

 in 10 c.cm. water), 1 grin. ; osmic acid 2 p.c, 25 c.cm. Owing to the 

 great brittleness of embryos fixed in this fluid all changes of liquid 

 should be made with pipette in the same dish, avoiding as far as possible 

 any movement of the embryos. 2. Stain in 0'5 p.c. pyrogallic acid in 

 the dark for twenty-four to forty-eight hours with several changes. 



* Journ. R.A.M.C., March 1914. 



t Journ. Morphol., xxv. (1914) pp. 1-87 (9 pis.). 



