306 JOURNAL OF SCIENCE. 
filtering and diluting if necessary.* This solution stains rapidly 
and intensely, but I think is inferior to the others mentioned in 
selective power. The best formula for the haematoxylin is that 
well known as Kleinenberg’s.f A saturated solution of calcium 
chloride in 70 ¥ alcohol, with the addition of a little alum, after 
being filtered is mixed with from six to eight times its volume 
of 70 Y% alcohol. To this is added a few drops of a concentrated 
solution of crystallised haematoxylin in absolute alcohol. The 
colour of the staining fluid thus formed should not be too dark, 
but a watch-glass full of it should appear nearly opaque when 
placed on a sheet of white paper. In this solution the Annelide 
should remain for half a day, and should then be transferred to 
strong alcohol, to be followed after twelve hours by absolute alco- 
hol. If the object is seen to be overstained (and it is often very 
difficult to adjust the strength of the solution and the time of 
immersion to the state of the specimen, so as to be quite sure of 
the result), a little hydrochloric acid (a drop to two ounces) 
should be added to the rectified spirit. 
For the carmine solution the modification of Beale’s formula 
recommended by Rutherford{ will be found the best. Ifthe 
specimen has been hardened in chromic acid, the addition of a 
little more ammonia may be found advantageous. This should 
be diluted with its own bulk of water, and the specimen allowed 
to remain in the solution for twenty-four hours, after which it 
may be transferred to strong spirit. Grenacher’s borax-carmine, 
which I have found a very excellent staining fluid for the Annelida, 
is prepared as follows :—To a 4 ¥ solution of borax in water add 
2.5 % of pure carmine; allow the solution to stand for two or 
three days, stirring it occasionally. Add to thisan equal bulk 
of 70 % alcohol ; allow it to stand for a week, and then filter, 
when it will be ready for use. Six to ten hours will be found 
sufficient to stain the Annelide very thoroughly ; it should then 
be transferred: to 70 ¥ alcohol, slightly acidulated, for a few 
hours, then placed in 90 / , and afterwards in absolute alcohol. 
Before being embedded the specimens should be placed for 
half-an-hour in creosote, and from that removed to a mixture of 
creosote and paraffin melted in a water bath. A very excellent 
embedding material is paraffin and vasellin, in the proportion of 
three parts of the former to one of the latter. This wax is very 
readily dissolved out from the sections by a mixture of carbolic 
acid and turpentine, and moreover it cuts extremely well. It 
will usually be found unnecessary to wet the knife. To preserve 
with certainty the order of the sections, they should be placed in 
series along the slide as they are cut, and, to prevent the possi- 
bility of disarrangement, the following process will be found of 
advantage.§ Each slide, after having been carefully cleaned and 
* Paul Meyer, Mittheilungen aus der Zool. Station zu Neapel, I. 
+ See Foster and Langley’s Practical Physiology, p. 252. 
{ Practical Histology, p. 172. 
§ Giesbricht, Mittheilungen aus der Zool. Stat. zu Neapel. 
