DE-ALCOHOLTSATION AND CLEARING AGENTS. 



81 



other sources, may be useful, but the figures must be accepted with some- 

 caution, on account of the variability of samples. The figures given for 

 balsam refer evidently to the resin in the solid state and not to the solu- 

 tions used for mounting, which are certainly much lower according to the- 

 lower index of the solvent. 



Air 1-000 



Methyl alcohol . . . 1*323 



Distilled water . . . 1*336 



Sea water .... 1-343 



Absolute alcohol . . . 1*367 

 Acetate of potash, saturated 



aqueous sol. . . . 1*370 

 Glycerin with an equal quan- 

 tity of water . . . 1-397 

 Glycerin, Price's . . . 1*460 

 Oil of bergamot . . . 1*464 

 Paraffinum liquidum . . 1*471 

 Olive oil .... 1-473 

 Oil of turpentine . . 1*473 

 Glycerin, " concentrated " . 1'473 

 Castor oil .... 1*490 j 

 See also the chapter on 



Cedar-wood oil, not thickened 1*510 

 Crown glass . . , 1*518 

 Cedar-wood oil, thickened . 1*520 

 Oil of lemons . . . 1*527 

 Oil of cloves . . . 1*533 

 Canada balsam (solid) . . 1*535 

 Creasote .... 1*538 

 Carbolic acid . . . 1*549 

 Oil of anise seed . . . 1'557 

 Anilin oil . . . . 1*580 

 Oil of cinnamon . . . 1*619 

 Sulphide of carbon . . 1*630 

 Tolu balsam . . . 1*640 

 Monobromide of naphthalin T66O 

 Solution of sulphur in sul- 

 phide of carbon . . 1*750 

 ' Examination Media." 



108. Choice of a De-alcoholisation or Clearing Agent. 

 Special directions for clearing are given when necessary 

 under the heads of the different organs and tissues. It will 

 suffice here to advise the beginner to keep on his table the 

 following : Oil of cedar, for general use and for preparing 

 objects for imbedding in paraffin, see "Imbedding Methods 

 Paraffin ; " clove oil, for making minute dissections in 

 cases in which it is desirable to take advantage of the 

 property of that essence of forming very convex drops on 

 the slide, and of imparting a remarkable brittleness to soft 

 tissues, and for much work with safranin, etc. ; oil of bergamot 

 which will clear from 90 per cent, alcohol, and which does 

 not extract coal-tar colours ; carbolic acid, for rapidly clear- 

 ing very imperfectly dehydrated objects. 



For special clearers for celloidin sections see " Collodion 

 (Celloidin) Imbedding Methods." 



109. Cedar Oil (NEELSEN and SCHIEPPERDECKER, loc. cit., 

 107). Thin, colour light yellow or greenish, odour slight 

 (of cedar- wood), evaporates slowly, is not changed by light, 

 is miscible with chloroform -balsam, and with castor oil. 



6 



