ZOOLOGY AND BOTANY. MICROSCOPY, ETC. 147 



for the Thoma- Jung, and for the Spengel-Becker microtomes. They are 

 shown in figs. 33 and 34, their natural size. 



In fig. 33 is shown the " cutter " or parer, as constructed for the 

 Thoma-Jung object-holder. It may, however, be fitted to any micro- 

 tome with a cylindrical object-holder. Its construction is extremely 

 simple. It consists of a stout ring h, the internal diameter of which is 

 exactly equal to that of the object-holder. The ring is immovably united 

 to the piece a, which in its turn is exactly like the paraffin cylinder 

 which fits into the object-holder. In the ring is seen the binding-screw c. 

 The paraf&n-holder d, which fits inside the ring, may be either solid or 

 hollow. 



The holes in d and a are for the purpose of turning round the 

 apparatus. While the object is being pared down the part a is fixed 

 firmly in the object-holder, and when the block has had its definition- 

 surfaces thus prepared, it is removed from the cutter and fixed on the 

 object-holder in such a way that it is cut in a direction perpendicular to 

 the surfaces. 



The second model, fig. 34, differs very little from the author's 

 original apparatus. In this newer model the stem a is straight, instead 

 of being bent at a right angle. This apparatus is intended to be used in 

 any ordinary object-holder, and is of such dimensions that movement in 

 any direction when it is fixed in the clamp is possible. This " parer " 

 fits into the apparatus e, which consists of two blocks of wood loosely 

 united by short metal wires. The wooden holder of course fits into the 

 clamp while the block is being shaved down. When the boundary sur- 

 faces have been satisfactorily adjusted to the paraffin block, the latter is 

 removed from the " cutter " or parer, and inserted into the wooden 

 holder wherein it is sectioned. 



CoLMAN, W. S. — Section Cutting and Staining. A practical guide to the prepara- 

 tion of normal and morbid histological specimens. 



viii. and 107 pp., 6 figs. 8vo, London (Lewis & Co., 

 136, Gower Street, W.O.), 1888. 



(4) Staining and Injectingr. 



New Stains for Microscopical Purposes.! — Prof. E. Zschokke gives 

 the results of his examination of the following six pigments, which he 

 has used for staining animal and vegetable tissues : — 



(1) Benzopurpurin B. An amorphous brown powder, soluble in 

 water, and giving a cinnabar red solution and corresponding stain. It 

 acts very much like acid fuchsin and is much superior to eosin, being 

 unacted on by alcohol, anilin oil, oil of cloves, &c. It makes a good 

 contrast stain to hsematoxylin, and can be used after Gram's method. 



(2) Benzopurpurin 4 B. An orange-red dye, soluble in spirit. The 

 sections should be transferred from spirit to the alcoholic solution of the 

 dye. It stains connective tissue orange. It is little altered by acids or 

 alkalies. It may be used sometimes as a double stain with logwood. 



(3) Deltapurpurin. A brownish-red powder, easily soluble in water. 

 Preparations are stained in two minutes a diflEuse purple-red. The dye 

 is very stable and not easily extracted. Like the preceding two, it may 

 be used as a contrast stain to hsematoxylin. 



(4) Benzoazurin. A brown powder, easily soluble in water, the 



♦ Zeitachr. f. Wisa. Mikr., v. (1888) pp. 465-70. 



L 2 



