or the fecundating Dust of the Date Tree. 6l 



loured matter from it, mixed, or perhaps combined with a 

 small portion of phosphate. 



A gramme of the same substance put into nitric acid 

 immediately assumed a yellow colour, and seemed to be 

 dissolved ; but in a few days the dust was separated and 

 occupied the upper part of the liquor. The latter had a 

 fine citron yellow colour ; it was precipitated abundantly by 

 lime-water, and this precipitate was ot a very deep yellow • 

 its nature vvas the same with that of the precipitate produced 

 by the ammonia in the preceding experiment. The pollen 

 thus treattd, when washed with distilled water assumed upon 

 drying a very intense yellow colour, and the form of soup, 

 to which desiccation gave semitransparency and hard- 

 ness. Placed upon burning charcoal, it softened, and an oily 

 substance exuded from every part of it : it soon left a light 

 charcoal behind it. The pollen had therefore undergone a 

 commencement of alteration on account of the nitric acid, 

 since it presented after being subjected to its action pro- 

 perties which it had not previously; it seems to have ac- 

 quired a greasy character, like the animal substances treated 

 by the nitric acid. 



This alteration indicated by the preceding experiment, 

 having appeared deserving of being better known, we re- 

 peated the experiment in the following manner : Sixteen 

 grammes of unwashed pollen were put into a glass retort 

 with nitric acid diluted to 30 degrees of the areometer. An 

 action between the substances was manifested upon the first 

 contact, and without the assistance of fire. The pollen ap- 

 peared to be softened and dissolved in the nitric acid; its 

 dust formed a homogeneous mass, semitransparent, and 

 presenting the consistence of soup. Soon afterwards, and 

 always in the cold, a gas was developed, which, slowly ex- 

 tricating itself in the midstof a thick matter, lifted it up like 

 beer-yeast when the process of fermentation is going on. 

 This gas was in a great measure azotic gas, mixed only with 

 a small quantity of nitrous tras. 



This mixture subjected to the action of a slight heat soon 



boiled, it produced a large volume of gas, which was, from 



the beginning to the end of the operation, a mixture of ni- 



2 trous 



