1090 -General Notes. [ October, 
containing ordinary alcohol. The latter process determines the 
degree of consistence of the imbedding mass. It can be made 
extremely hard by repeated use of strong alcohol. After a few 
trials it will be easy to find the convenient degree of consistence 
for each specimen. 
If the temperature of the alcohol steam is more elevated, it 
will be found that the imbedding mass, instead of shrinking, will 
appear to increase in volume, innumerable air-bubbles developing 
in the emulsion. This can be easily avoided by using lower tem- 
peratures. Another danger, however, exists in the holes which 
the pins make in the walls of the paper boxes. The emulsion, 
before hardening, is so very liquid that it will pass through the 
smallest opening ; this renders it necessary not to withdraw any 
of the pins from the sides of the paper box, and to use boxes 
without any openings. It will be found that this mass adapts 
itself perfectly to all surfaces of the specimens without pene 
trating into their interior structure, and that it can be cut admi- 
rably at all thicknesses down to 0.003™™ Another very agree- 
able quality results from the fact that the newly prepared emul- 
sion will adapt itself readily to hardened pieces. This enables 
us to spread out fine membranes on pieces of the hardened im- : 
bedding mass, and subsequently to imbed both in the way just 
described. ; 
After this praise of the egg-emulsion, it will be just to eae | 
y which is occasionally disagreeable. It cannot ao 
easily detached from the sections, and we have no means of dis 
solving it in media which do not injure the objects. The mass 
also colors in all the staining fluids generally used, and therefore - 
The latter inconve 
nience should in all cases be avoided by coloring the T a 
in toto before imbedding. For this purpose the fluids of Gret 
bly, a solution of so-called ce//oidin. If this substance cant s | 
general be cut to such extreme delicacy as the album! 
just described, it has a great advantage in being extremely pel 
cid. The original communication of the last-nam 
ve er 7 
1 Arch. f. Mikr. Anat., xvi (1879), p. 465- 
2 Arch, f. Anat. u. Physiol. (Anat. Abtheil,), 1882, 
