ALCOHOLS. 25 



ALCOHOLS. 



ALCOHOL (Ethyl Alcohol). 



The known disinfecting value of spirits of wine, 

 or alcohol, 1 depends upon its fatal action on all 

 protoplasm ; hence its application as a preservative 

 for animal and vegetable preparations. Absolute 

 alcohol has the property, in common with peros- 

 mic acid, of rendering protoplasm rigid, and it is 

 thus applicable in studying the more intimate 

 structure of protoplasmic bodies, the division of 

 the nucleus, etc. Its avidity for water causes the 

 protoplasm to contract from the cell-wall, so that 

 the ectoplasm becomes visible ; and the same 

 peculiarity is taken advantage of when we employ 

 alcohol for hardening tissues that are too soft for 

 section-cutting when fresh. It may also be used 

 advantageously for removing the air from intercel- 

 lular spaces, etc., in preparations, since it pene- 

 trates into capillary cavities much more readily 

 than water does. In difficult cases warming the 

 sections often helps this action, alcohol being 

 added from time to time to replace that lost by 



1 Dippel: Das Mikroskop, I., p. 282. DeBary: Vergl. Anat, p. 86. 

 Nageli: Das Mikroskop, 1877, p. 476. Sachs: Bot. Zeit., 1864, Nos. 12- 

 13. Weiss: Allg. Botanik, 1878, pp. 182, 185. Tangl: Protoplasma der 

 Erbse.- Sitzber. wien. Akad., Abth. i, 1877-8. Strasburger : Zellbildung 

 und Zelltheilung, 1875, P- 2 ! Befruchtung und Zelltheilung, 1878, p. 38. 



