TURPENTINE-^XYLENE 



329 



Turpentine. — This may be used to dissolve paraffin from 

 sections which have been cut from material imbedded in paraf- 

 fin. See also under Carbolic Acid. 



Venetian Turpentine. — To prepare a mounting medium 

 from Venetian turpentine, the product as it comes from the apothe- 

 cary is diluted with an equal volume of strong alcohol, and after 

 the mixture has become clear by long standing or by filtering 

 after being well shaken, it is thickened somewhat on the water- 

 bath. Objects may be' mounted directly from strong alcohol 

 into Venetian turpentine as above prepared. Objects which 

 are found to shrink by this treatment may be transferred from 

 strong alcohol to a mixture of 10 parts of the turpentine with 

 100 parts of alcohol. The alcohol is then to be withdrawn from 

 this mixture by placing the latter, together with a dish of calcium 

 chloride, under a bell-jar. In order to keep the mixture of tur- 

 pentine and alcohol from mounting the sides of the vessel which 

 contains it, the rim of the vessel should be coated over with hot 

 paraffin. The turpentine hardens quite slowly, and in order to 

 quickly fasten a coverglass to the slide when the turpentine is 

 being used for a permanent mount, a wire which has been heated 

 in a flame should be quickly drawn around the edge of the 

 coverglass. 



Xylene. — This is used as a solvent for paraffin, either in re- 

 moving paraffin from sections or in preparing a dilute solution 

 of paraffin to be used in the gradual infiltration of tissues with 

 this substance. Used also as a solvent of Canada balsam. Xylol 

 is the trade name for xylene 



