218 - General Notes. [ February, 
MICROSCOPY .' . 
Mayer’s Meruop oF Fixinc MIcroscoPicaL Secrions?—The 
new fixative proposed by Dr. Mayer is prepared by mixing tle 
filtered white of eggs with an equal volume of glycerine? A little 
carbolic acid may be added as an antiseptic. A very thin and 
even layer of the fixative is painted upon the object-slide, which 
is then ready for receiving the sections. After the sections atè 
placed, the slide is warmed a few minutes in the oven of a water- 
bath, just Jong enough to melt the paraffine. The paraffine 1$ 
next dissolved away from the sections by turpentine, the turpen- 
tine removed by alcohol, and the sections then colored 2m silit 08 
the slide. ae nded. 
As acoloring fluid, a strong alcoholic carmine is recomme 
It is prepared as follows: a 
issolve four grams carmine in 100°% alcohol bis | 
cent) by boiling about thirty minutes, adding thirty yr | 
strong hydrochloric acid during the boiling. The 50 erie 
‘should be filtered while hot, and the acid carefully neutrali a. 
adding ammonia until carmine begins to be precipitated. eate 
This fluid, which may require to be filtered a second T obtain 
cooling, stains uncommonly quick, deep and diffuse. +0 "iy ; 
a differential staining, it is well to stain deeply, and then par" 
decolor by washing with acidulated alcohol. er 
The decoloration should be checked at the moment 
film of the fixative become nearly or quite colorless. 
a 
PERCHLORIDE OF IRON AS A REAGENT FOR PRE D re | 
MARINE ANIMALS.—In experimenting with a delicate class > cip 
rine infusoria (Tintinnodea), Dr. Folt found that pi rwicadl ; 
common use for instantaneous killing, such as picro-su P etic adh 
osmic acid alone or in combination with chromic and paral : 
and corrosive sublimate, failed to give successful pre ont quite 
He finally succeeded with perchloride of iron, 4 ae id o 
new in histological technique. An alchoholic solatii a 
about two per cent will answer ordinary purposes; D4 large nue 
solution should be used in case it is desired to kill a er to tut 
ber of animals in a large vessel. It will not do, bor - 
a saturated solution directly into sea-water, as precip! aration 
be copiously formed, which would utterly ruin the i mot% | 
After the animals have sunk to the bottom of the Nein adde 
the water may be turned off, and seventy per cent an 
In order to remove from the tissues the ferric salts hol ¢ 
them, it is necessary to replace this alcohol with alco 
ing a few drops of hydrochloric acid. | 
1 Edited by Dr. C:O. WHITMAN, Mus. Comp. Zool., Cambridge opted 
; Dr. Paul Mayer. “ Einfache Methode zum Aufkleben mikros 
er! : en p ] 
Schmitte. Mittheil Zoolog. Station at Naples, 1v, p. 521, 1883. Zool. yav a 
t Fol, Beiträge zur histologischen Technik. Zeitschr. f. w155- 
491, 1883. ; 
dhering ® 
