ORGANIC SALTS. 43 



intensified by transferring the section to dilute 

 sulphuric acid. If it is desired, the reagents may 

 be mixed before using. 



Since this anilin salt is found in the market only 

 in a very impure and barely soluble form, it is bet- 

 ter to replace it by the next. 



CHLORIDE OF ANILIN 



Is used in aqueous solution for the same purposes 

 as sulphate of anilin, and in the same manner, 

 except that the acid used must be hydrochloric. 1 

 An alcoholic tincture of either anilin salt may 

 replace the aqueous solution, and the colors pro- 

 duced are then more intense. 



CHLORAL. 



This has been recently introduced into micro- 

 chemistry by Meyer. 2 It is employed in aqueous 

 solution : five parts of chloral to two parts of 

 water; and should be used at a temperature of 15 

 C, as crystals are precipitated at lower tempera- 

 tures. Its effect upon fats and volatile oils is 

 similar to that of alcohol. It dissolves the same 

 saccharine and amylaceous matters (Kohlenhy- 

 drate) as water, and causes the swelling of starch 

 grains. It swells or dissolves protein matters, and 

 is, therefore, frequently useful in clearing tissues. 



1 Hohnel : Ueber Kork, etc., p. 21. 



2 Arthur Meyer : Das Chlorophyllkorn, Leipzig, 1883. 



