Organic Matter in Water. 195 



ter of an hour, it is so firm that the capsule containing it may be 

 inverted without the jelly falling out. The matter thus gelatinized 

 by sulphuric acid is peculiar to this plant. The author has applied 

 sulphuric acid to the infusion of at least 150 flowers, without any 

 similar result taking place. The author conceives that the gela- 

 tinising matter is a distinct vegetable prjnciple, to which he gave 

 the name of Leucanthemine. To support this view, he drew a com- 

 parison between it and the coagulable matters, both of the animal 

 and vegetable kingdoms, viz. animal albumen, casein, fibrin, and 

 vegetable albumen. In drawing this comparison, the author de- 

 scribed some remarkable properties of these albuminous matters, 

 which have escaped the observation of all the investigators of the 

 chemistry of organic substances, and some of which he had been in 

 the habit of exhibiting in his lectures for nearly half a century. 

 These are, principally, that sulphuric acid dissolves the albuminous 

 matters in the cold, and yields a nearly colourless solution, without 

 altering the nature of the albumen. But if the liquor be heated to 

 160°, it acquires an extremely beautiful rich crimson hue, during 

 which change the nature of the albumen is totally altered. Muri- 

 atic acid acts upon albuminous matter nearly in the same manner; 

 but the colour which the solution acquires by being heated is a very 

 rich purple. The jelly from the Leucanthemum affords no crimson 

 colour with sulphuric acid. After pointing out other circumstances 

 of difference, the author gave his opinion that the Leucanthemine 

 ought to be considered as a distinct substance sui generis, another 

 vegetable principle ; and concluded with expressing his hope that 

 the Camellia, Magnolia, and Chrysanthemum furnish three to the 

 long list of vegetable proximate principles. 



2. On certain Negative Actions of Light. By Professor Moser 



of Kcenigsberg. In a Letter to Sir David Brewster. 



3. On the Specific Gravity of certain Substances commonly 



considered lighter than Water. By Dr Davy. 



Monday^ 11 th April 1843. 



The Right Honourable Lord GREENOCK, Vice-President, 



in the Chair. 



The following Communications were read — 

 1. On the presence of Organic Matter in the purest Waters 

 from Terrestrial Sources. By Professor Connell. 

 It must be well known to chemists, that when solution of acetate 



