ZOOLOGY AND BOTANY MICROSCOPY, ETC. 
231 
(2) Preparing- Objects. 
New Preparation for Rapidly Fixing* and Staining Blood.* — 
Dr. L. Jenner has introduced to histological technique a solution which 
works admirably as a blood-film fixative and stain. It is made in the 
following way: — Equal parts of a 1*2 per cent, to 1*25 per cent, solu- 
tion of Griibler’s water-soluble eosin, yellow shade, in distilled water, 
and of a 1 per cent, solution of Griibler’s medicinal methylen-blue in 
distilled water, are mixed together in an open basin and thoroughly 
stirred with a glass rod. After 24 hours the mixture is filtered, and the 
residue dried either in the air or in an incubator at (not exceeding) 
55° C. When quite dry the residue is scraped off the filter and 
powdered. It is then again shaken up with distilled water and washed 
on a filter, and after having been dried again is powdered. For use, 
0*5 grm. are shaken up with 100 ccm. of pure methyl alcohol, and the 
filtrate used as the fixative stain. The solution keeps well. 
The stain may also be made by dissolving the eosin and methylen- 
blue in methylic alcohol, and mixing them in the proportion of 125 ccm. 
of a 0*5 per cent, solution of eosin and 100 ccm. of a 0*5 per cent, 
solution of methylen-blue. 
Cover-glass preparations are made by pouring a few drops of the 
solution on the dry film, and allowing the solution to act for one to 
three minutes. The stain is then poured off, and the cover-glass rinsed 
in distilled water until the film assumes a pink hue (5-10 seconds). 
The cover-glass is then dried, preferably in the air. The red discs are 
terra-cotta coloured ; the nuclei of white corpuscles blue ; the platelets 
mauve ; the granules of the polymorpho-nuclear white cells and of 
myelocytes are red ; those of the basophile or mast cells dark violet ; 
and bacteria, filariee, and malaria parasites blue. 
The inventor claims for the new method that it demonstrates more 
plainly, readily, and simply than those in general use. 
(3) Cutting-, including Imbedding- and Microtomes. 
New Large Model Zimmermann Microtome. f — Dr. van Yfalsen 
describes this instrument, which has been constructed especially for the 
cutting of such large objects as brain-hemispheres. As will be seen from 
figs. 63, 64, it closely resembles the well known Minot-Ziromermann 
type. The cast-iron base-plate B is 24 by 30 cm., and on its right 
hinder quadrant are two short vertical pillars C C, in whose upper 
portion a horizontal axis D is inserted. The axis is operated by the 
wheel E, whose scollops are necessary in order to attain the requisite 
balance. The working is delightfully regular and easy, in spite of the 
rather great weight (33 kg.). The size of the wheel renders it neces- 
sary to set the machine either on the edge of a table or on a specially 
made wooden block (as in fig. 64). At its left end the horizontal axis 
is connected with the excentric lever G, whereby the rotation of the 
wheel produces a vertical movement of that part of the instrument 
which carries the object and the screw-adjustment. G has a groove 
parallel to its length (fig. 64 ), in which the small horizontal arm can 
* Lancet, 1899, i. pp. 370 -L 
f Zeitichr. f. wiss. Mikr., xiv. (L89S) pp. 145-55 (2 figs, and 1 pi.). 
