ue Notes ¢ on SCIENTIFIC > RESEARCH. | ie aA 89 
daibet. peas: cananga, citronella, daraway, netted, bitter orange, rue, savin, mustard | 
and juniper-berry oils are named “the transparence-producing oils”. 
In addition to these oils noted only by Unna and Golodetz, 19 other oils were up 
to now used in micro- technology, of which lemon, eucalyptus, fennel, lavender, 
rosemary, peppermint, sandalwood, spike, and thyme oils can be dispensed with entirely, 
and need be no more mentioned. 
Oil of aniseed on account of its high rehactive index, is used for examining or 
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“preserving many less. Me repenet or F eionely: refractive objects, dental enamel for 
example: Raise , 
Oil of bergamot is suitable for conve sections, since the sections then flatten, 
‘become stiff, but do not however, contract. _Oil of bergamot is also recommended as 
3 intermedium for paraffin. — ) 
Cajuput oil is used for colouring the Pipobads (Nissl’ s bodies) in the ganglia cells 
according to the method of F. Nissl, and isscuins eclloidin according to the process 
of Carnoy and Lebrun’). 
- Cedarwood oil concentrated. (thickened) till its refractive index = 1 .515 serves as 
~ medium; in viewing a preparation with immersion lenses, no cover slip is needed. — 
Further, small objects can be cut up in the oil and preserved. According to P. Mayer: 
cedarwood oil renders good service in testing the purity of eaaltar dyes, since oe 
are mostly insoluble in it. 
~~ Gaultheria oil (oil of wintergreen) is Jes for thinning are balsam, as inter: ; 
medium for balsam and paraffin, and also.as a medium. Mayer was able to preserve 
unaltered a specimen coloured with “Hamalaun” in the’ oil. 
Linaloe oil is very good to use in order to transfer objects from alcohol into 
_ balsam, since it does not dull like oil of cloves, but remains colorless. 
a ne A ; ie » 
- Oil of cloves has been more used than any other oil, especially as intermedium  —__ 
for balsam, or also as medium. It is often used for dissolving aniline dye stuffs, for 
the purposes of Staining, or to extract over-staining. | . 
ey . One has found use for origanum oil in the double inbedding in celloidin and 
sy "paraffin, and in making sections lighter coloured. : 
Already in 1834 oil of turpentine was used by A. Retzius to increase the cae 
‘parency of paper-thin laminz of teeth, which laminae had been prepared with the 
aid of file and saw”). ‘The oil is now used to thin balsam, to dissolve rosins (colo- 
- phony, dummar) since these harden much more slowly than when dissolved in xylene 
and chloroform. Strasburger and Koernicke use oil of turpentine as medium for alge; 
aS a medium for aniline dyes, resinised or ozonised oil of ae is Praised by. 
_P. Ehrlich and W. Rubaschkin. | 
Cinnamon oil with its much higher refractive index than that of balsam or resin, 
_ is used with advantage instead of oil of cloves as intermedium or medium. | 
_____ The various sorts of micro-technique (paraffin-, celloidin-, ice-, gelatine-, and rosin- 
technique), which are eae deserived in eee work, cannot be gone into 
further here. 
_ Only a few volatile oils are “suitable as media for Sennen BPeaaE ations: Most 
of them evaporate too rapidly or deteriorate under the cover glass. The only exception 
is cedar-wood oil., It is similar to balsam in that it resinifies and thickens in lying 
_ long under the cover glass; at the same time its refractive index approximates to that 
of ae which is of special importance in- making observations with immersion lenses. 
1) Cellule 13 (1897), “A. —.% Arch. f; Anat. u. Phys. 1834, 487. 
