324 Prof. Pringsheim on Hypoclilorin and the 



in Elodta, Callitriche, &c, the heating of the whole plant in 

 water of 50° C. for from a quarter to half an hour is sufficient 

 for the complete suppression of the hypoclilorin reaction. 

 Other plants require that the action should be of longer dura- 

 tion or the temperature higher. A brief boiling of the tissue 

 in water or treatment of the plant with the vapour of boiling 

 water leads, however, to the same result in all of them. 



After such treatment as has been stated, the hypoclilorin 

 reaction with hydrochloric acid no longer makes its appear- 

 ance in the tissues, or at any rate not to the same extent as in 

 the fresh tissues. 



There is especially a regular absence of all those larger 

 crystalline scales which the hypochlorin-mixture produces in 

 the fresh plant under the influence of hydrochloric acid. In 

 the tissues heated to a considerable temperature with water, 

 or boiled, or subjected to distillation with water (even when 

 they are subsequently treated with hydrochloric acid) there 

 are now at the periphery of the chlorophyll-bodies only those 

 few and isolated small oil-drops which, as I have already 

 described, separate from the fundamental substance by the 

 action of heat alone, and which, without undergoing any 

 further alteration by hydrochloric acid, obstinately retain the 

 fluid state even under a continued application of heat. 



It consequently appears the simplest course to refer the 

 interruption of the hypoclilorin reaction by heat, and the non- 

 appearance of the crystallizable segregations when the green 

 tissues are merely heated, to the fact that the peculiar matter 

 in the hypochlorin-mixture which causes its crystalline soli- 

 dification is destroyed in the chlorophyll-bodies or dissolved 

 by warm water, or becomes volatilized with the hot aqueous 

 vapours. 



The latter is my opinion. This microscopic behaviour of 

 the chlorophyll-bodies when heated and the above concep- 

 tion are in agreement with certain attempts which, under the 

 supposition that hypoclilorin is a volatile substance, I have 

 made with the view of preparing it on the large scale for 

 chemical analysis, by the distillation of green tissues with 

 superheated steam. 



In this way, in fact, we may obtain from the green tissues 

 of very different plants (even of such as possess in the tissues 

 in question no known specific essential oil) a small quantity 

 of a homogeneous essential oil, which separates from its solu- 

 tion in ether in colourless microscropic crystals, assuming the 

 form of small, carved, isolated, dendritically-branched needles, 

 which are remarkably similar to the hypochlorin-needles 

 such as separate under microchemical treatment from the hy- 



