ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 853 



(5) Mounting:, includlngr Slides, Preservative Fluids, &o. 



Treatment of Sections which have been imbedded in Paraflin.* — 

 Dr. H. Strasser removes the parafiBn with benzin or with warmed turpen- 

 tine, after which the sections are placed in chloroform for a short time and 

 then in 60 per cent, spirit. From the spirit they are transferred to solu- 

 tions, either watery, or mixed with a little spirit. 



When treating serial sections the author has somewhat modified his 

 former method for producing paper plates covered with gum and collodion. 

 Sheets of stout smooth writing paper are pinned down to any flat surface 

 and brushed over with a solution of gum arabic. With the mucilage of 

 gum arabic of the pharmacopceia is mixed 1/5 vol. of glycerin. This 

 addition renders pressing the sheets superfluous. When the gum layer is 

 dry, it is coated over with collodion thinned down with ether to the con- 

 sistency of glycerin, and 1/100 vol. of castor oil added to impart elasticity. 

 The collodion mixture should be smeared on with a large soft brush, and 

 with practice several layers can be put on in a few minutes. Thus pre- 

 pared they are folded in the middle, the paper side outwards, and laid 

 aside till wanted. The sections are stuck on with the following mixture : — 

 Collodion 2 vols, ether 2 vols, castor oil 3 vols. Care must be taken that 

 no air remain under the section, and when it is fairly fixed, the surface is 

 brushed over with the same solution. The plates thus prepared are 

 then immersed in benzin or turpentine for a half to several hours. 

 Turpentine is to be preferred for most reasons, while the chief advantage of 

 benzin is that the plates require less careful manipulation. The plates 

 are then placed in chloroform, from which in fifteen minutes or longer 

 they are transferred to 80-85 per cent, spirit, wherein the collodion is 

 gradually hardened. 



Fixing Sections.f — Clouding of the shellac used for sticking on sections 

 can be avoided by dissolving the shellac in carbolic acid. But as the acid 

 attacks many tissues — for example, the skin of vertebrates — the author re- 

 commends the warm slide to be smeared with an alcoholic solution of sbellac, 

 and then allowed to cool. The sections are tlien placed on dry, and having 

 been carefully smoothed out, are exposed to the vapour of ether. This is 

 most easily and simply done by putting the slide in a vessel, at the bottom 

 of which is some ether. The vessel is then closed, and in about half a 

 minute the sections are saturated with ether, which is afterwards removed 

 in a water-bath. The further treatment is as usual. Softening the shellac 

 with ether vapour is not so safe for brittle sections as the carbolic 

 shellac. As chloroform also softens shellac, the use of chloroform balsam 

 is rather dangerous ; it is safer to use turpentine or benzol (not benzin) 

 balsam. 



The formula given for the author's albumen adhesive is : — Albumen 50 cc. ; 

 glycerin 50 cc. ; salicylate of soda 1 gr. ; the mixture is to be well shaken, 

 and then filtered into a clean bottle. Is said to keep for at least three 

 years. 



Eternod's Turntable "to serve several purposes."^ — Prof. A. Eternod 



has utilized the body of the turntable (fig. 232), so that it is now available 

 for different purposes, and this is etfected without increase of space, a 

 desideratum to many workers. The turntable is at a, the upper surface 



* Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 44-6. 



t Internat. Monatschr. f. Anat. u. Physiol., iv. (1887) Heft 2. 



X Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 41-2 (1 fig.). 



