290           THE MICROTOMIST' S VADE-MECUM
which are dissolved in 556 c.c. water. Carbonic acid is then 0
passed through the solution to saturation. Two volumes of (JP
the solution are mixed with 2 vols. water and 1 vol. solutio g4
Milleri, and the embryos are macerated in the mixture for one   04ots
or two days. Equally good results were obtained by the use
of the following simpler solution:                              by in
463. Saliva, Artificial (Calberla's second formula):           tal
Calcium chloride        .     .         0-4           la
Sodium chloride    . .     .    .       0i3i
Phosphate of soda       .    .     .    0*2
Calcium chloride           .       .    02             mutint
This is dissolved in 100 parts of water, saturated with      sufe
carbonic acid, and the solution combined with water and         olOd
solutio Miilleri in the proportions given above in the first    ithe
formula.                                                        (inL
In either case, the Miller's solution may be replaced by a, roion
2- per cent. solution of chromate of ammonia. The best seis
results were obtained when the solutions were saturated with     edior
the CO just before using. Vl17f
The tissues are isolated by teasing and shaking, and speci- o M
mens mounted in concentrated acetate of potash. glm
464. Corrosion (Altmann's methods ').-The applicability of   ping
the principle of corrosion to histology is found in the fact monu
that whilst almost all animal tissues are very quickly de-       If
stroyed by eau de Javelle, yet fats, and particularly fats      uter
hardened by osmic acid, withstand its action for a long time.   nftr
If then you introduce some fat or other into a tissue, Ie
harden it with osmic acid and corrode the tissue with eau       hpl
de Javelle, you will obtain a mould, in osmium-blackened         Fro
and hardened fat, of the spaces you had filled with the fat      0,6
introduced.
The fat used by Altmann is olive oil; he also uses the fat.   aln
I 'Arch. Mik. Anat.,' xvi (1879), p. 471, et seg.     i