536 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



TriVjondeau method, and bj Loeffler's flagella-staining method. Good 

 results were obtained, and are shown in the coloured iUustration. 



The Fontana-Tribondeau method is thus given. A smear is made 

 with the emulsion of the cortex, and then fixed for a minute in the 

 following fluid : acetic acid, 1 c.cm. ; formol, 2 c.cm. ; distilled water, 

 100 c.cm. Next it is washed in running water, and then mordanted 

 for :iO seconds in carbolic acid, 1 c.cm. ; tannin, 5 grm. ; distilled water, 

 100 c.cm. The mordant is heated until it vaporizes. After another 

 wash the film is treated for ?>() seconds with the following solution 

 heated till it vaporizes : nitrate of silver, 25 grm. ; distilled water, 

 100 c.cm. ; liquid ammonia, as many drops as are necessary to re-dissolve 

 the precipitate which is formed when the ammonia is first added. Wash 

 in running water and dry. The spirochaetes are brown on a yellow 

 ground. 



The smear method is much more reliable and rapid than the 

 method of sections. 



Method of Obtaining Pure Trypanosoma Strains.* — R. Oehler 

 makes further remarks upon his method of isolating trypanosomes. 

 This method consists of the separating off of single trypanosomes in 

 capillary glass tubing, and then infecting animals with these isolated 

 organisms. The author has made further use of his method, and has 

 been able by this single-organism injection method to infect animals to 

 the fourth passage. Incubation period and course of disease remained 

 unaltered. He further was able in this way, and by injecting infected 

 animals with various doses of salvarsan, to obtain races of trypanosomes 

 possessing different degrees of resistance to arsenic, to investigate the 

 extent to which such resistance is affected by subsequent passage, and 

 to compare resistant and non-resistant strains. 



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



New Method of Mounting Microscopical Preparations.! — 0. 

 Cepede has devised a method of mounting microscopical preparations 

 so that they can be examined from the upper and lower surfaces, and 

 by means of high powers. An ordinary slide is ground out so as to 

 leave an aperture 19 mm. in diameter, and in such a way that a pro- 

 jecting edge is left all round (fig. 78,^). On this edge is placed a 

 coverglass with the specimen ; this is then covered with the mounting 

 medium (balsam, gelatin), and then another slip (fig. 78, ^) sHghtly 

 larger is imposed. 



In addition to the advantage of being able to examine a preparation 

 from the upper and under surfaces, the method will be found convenient 

 for stacking the slides together, so that risk of damage to the specimens 

 is altogether obviated (fig. 78, ,i). 



Electrically -heated Object-carrier for Microscopes.J — F. G. 

 Cottrell describes how a small object-slide with gilded edges can be 



• Centralbl. Bakt., Ite Abt. Grig., Ixx. (1913) pp. 110-11. 

 t Comptes Rendus, clvi. (1913) pp. 683-5 (1 fig.). 



I Journ. Amer. Chem. Soc, xxxiv. (1912) p. 1328 (1 ^g.) ; and Deutsche 

 Mechaniker-Zeitung (1913) pp. 115-16. 



