or the fecundating Dust ^of the Date Tree. 63 



bodies which must have escaped the effects of the nitric acid. 

 When put upon burning coals it was dissipated, after being 

 fused, into a pungent smoke hke that of fat; but it left a 

 more voluminous charcoal than the latter. When retained 

 some time in the mouth it produced at first a sensation of 

 bitterness, and then of rancidity, like common fat, when 

 treated in the same way- It no longer gave ammonia in 

 any perceptible quantity upon distillation, which seems to 

 prove that all the azot had been separated; cold alcohol 

 did not dissolve it, but only took up a small portion of it 

 by means of heat. Thus it cannot be doubted that this sub- 

 stance is a kind of oxygenated fat, or of artificial adipocire 

 nearly similar to that prepared with hog's lard and the nitric 

 acid. This fat was not pure ; it contained, as has been 

 just mentioned, a yellowish dust, which was not pollen, 

 neither was it an adipose substance, but it must have 

 become so by a longer continued action of the nitric 

 acid. 



§ X. Examination of the Pollen by the Alkalis ^ and after 

 Putrefaction. 



The caustic alkalis acted upon the produce of the date tree 

 in the same way as upon some dry, pulverulent, or animal 

 matters. This pollen when shaken with a ley of very caustic 

 potash, seemed to be dissolved even in the cold; and it be- 

 came soft, assuming a kind of transparency. This mixture, 

 when heated, bubbled up and was covered with froth ; it 

 exhaled a distinct ammoniacal smell ; when filtered after a 

 few minutes ebullition, the liquor was of a brownish yellow 

 colour ; it gave a slight precipitate by the acids, and presented 

 the characters of a soap. 



Thiity-two grammes of the seminal powder of the date 

 tree, not washed, were put inlo a flask with an equal quantity 

 of distilled water ; after having agitated the mixture in or- 

 der to form a paste, the vessel was closed, and the soft mat- 

 ter was abandoned for about two months in summer, ex- 

 posed to all the variations of heat which the atmosphere un- 

 derwent during this period. 



The substance was at first covered with white mould, 



which 



