ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 159 



Modification of Schiefferdecker's Celloidin Corrosion Mass.*— Dr. 

 F. Hochstetter has devised a modification of Schiefferdecker's celloidin 

 corrosion mass, whereby crumbling of the mass and any brittleness after 

 the addition of a large quantity of dye are prevented. 



It is recommended to mix washed porcelain earth (kaolin) with 

 celloidin. The porcelain earth is rubbed up with ether, to which cobalt 

 blue, chrome yellow, or cinnabar is added. To this celloidin of the 

 consistence of honey is added. The quantity of the kaolin to be used 

 depends on the size of the vessel to be filled. If the whole distribution 

 area of a vessel is to be injected, the syringe should at first be filled with 

 a thin injection mass containing less porcelain ; afterwards a thicker 

 mass should be used. Teichmann's screw-syringe is the most suitable 

 instrument for the purpose. A small quantity of pure ether is first 

 injected; this done the mass is squirted in, at first pretty quickly, but 

 afterwards more slowly, and the pressure of the piston-rod is kept up 

 until the mass begins to set in the large vessels. This method may be 

 'advantageously employed for demonstrating the vessels in bone or those 

 lying immediately upon it, but for " parenchymatous " organs this mass 

 is not to be recommended. The preparations are macerated in the cold, 

 bleached, &c. 



Hamilton, D. J.— Method of combining Weigert's Haematoxylin-Copper Stain 

 for Nerve-fibre with the use of the Freezing Microtome. 



Joum. of Anat, XXI. (1SS7) p. 444. 

 Light ox, W. K. — Notes on Staining Vegetable Tissues. 



[Cut a fresh greeu stem and place the newly cut end in one of the usual 

 staining solutions. The colouring matter will gradually be absorbed and 

 distributed through the tissues.] 



Amer. Hon. Micr. Jovrn., VIII. (1887) pp. 194-5. 



Wasseezug, E. — Principalis procedes de Coloration des Bacteries. (Principal 



processes of staining Bacteria.) Joum. de Bot., I. (1887) pp. 299-803, 321-4. 



(5) Mounting-, including Slides, Preservative Fluids, &c. 



Fixing Sections.! — Of the three fixatives now in general use — 

 shellac, collodion, and albumen — shellac is considered the best for 

 objects coloured in toto. The carbolic-acid shellac introduced by Dr. P. 

 Mayer has been found to be unreliable in some respects. Carbolic acid 

 warm is injurious to some tissues, e. g. the dermis of vertebrates. The 

 alcoholic solution is a perfectly harmless fixative. The method of using, 

 now described by Dr. Mayer, and which differs in important points from 

 the one prescribed by Giesbrecht, is as follows : — 



(a) The object-slide, heated to about 50° C, is coated with shellac in 

 the usual manner, by drawing a glass rod wet with the solution once or 

 twice over its surface. As soon as the slide is cool and the film of 

 shellac hard and no longer sticky, the sections are arranged dry, and 

 then gently pressed down by means of an elastic spatula (horn or metal) 

 until they lie flat and smooth on the slide. 



(6) Expose the slide thus prepared to the vapour of ether. For this 

 purpose the slide may be placed in a glass cylinder of suitable size, and 

 closely stoppered. The cylinder is placed in a horizontal position, or, at 



* Anat. Anzeig., 1886, pp. 51-2. 



t Intemat. Monatsschr. f. Anat. u. Physiol., iv. (1887) Heft 2. Cf. Amer. 

 Natural., xxi. (1887) pp. 1040-1, and tbis Journal, 1887, p. 853, where the author's 

 name was omitted tbrough the note being separated from others in printing. 



