DE-ALCOHOLISATION AND CLEARING AGENTS. 83 



cautions. I consider this to be one of the best of clearing- 

 agents, and valuable on account of the properties to which 

 attention has been called above. New clove oil washes out 

 anilin colours more quickly than old. It is well to possess 

 trustworthy samples of both new and old oil. 



111. Cinnamon Oil (Erratim " Carmel oil " in previous editions) 

 greatly resembles clove oil, but is in general thinner, and is more highly 

 refractive. An excellent medium, which I particularly recommend. 



112. Oil of Bergamot (SCHIEFFERDECKER, Arch. Anat. u. 

 Phys., 1882 [Anat. Abth.], p. 206). This oil clears 95 per 

 cent, alcohol preparations and celloidin preparations quickly, 

 and does not attack anilin colours. I think that this is 

 valuable medium, and though I do not agree with Schieffer- 

 decker in thinking its action superior to oil of cloves, I think 

 it should always be kept at hand. 



Bergamot oil is, I believe, the least refractive of these 

 essences, having a lower index than even oil of turpentine. 



SUCHANNEE (Zeit. f. iviss. Mik. } vii, 2, 1890, p. 158) says 

 that bleached, colourless bergamot oil will not take up much 

 water, whereas a green oil will take up as much as 10 per 

 cent. 



VAN DER STRICHT (Arch, de Biol., xii, 1892, p. 741) says 

 that bergamot oil will, with time, dissolve out the fatty 

 granules of certain ova. 



113. Oil of Origanum (NEELSEN and SCHIEFFERDECKER, Arch. 

 Anat. u. Phys., 1882, p. 204). Thin, light brown colour, 

 odour not too strong, ag'reeable, does not evaporate too 

 quickly, is not changed by light, is miscible with chloroform - 

 balsam and with castor oil. Ninety-five per cent, alcohol 

 preparations are cleared quickly, and so are celloidin sec- 

 tions, without solution of the celloidin. Anilin colours are 

 somewhat extracted. 



For work with celloidin sections care should be taken to 

 obtain. 01. Origani Cretici (" Spanisches Hopfenol "}, not 01. 

 Orig. Gallici (v. GIBSON ; see Zeit. f. wiss. Mik., iv, 4, 1887, 

 p. 482). Specimens of origanum oil vary greatly in their 

 action on celloidin sections, arid care should be taken to 

 obtain a good sample. 



