or the ftcuji dating Dust of the Date Tree. 53 



1. The pollen of the date tree has an acidulated and dis- 

 agreeable taste. 



2. When mixed with the tincture of turnsole it reddens it 

 perceptibly. 



3. When washed with warm water, it communicates to 

 it a yellowish colour, and a very sensible acidity. 



4. This infusion is precipitated in a canary yellow by 

 lime-water and ammonia ; the liquor which swims above 

 the precipitate is of a golden yellow. 



5. Solution of acetateof lead, of nitrate of mercury, and of 

 silver, is precipitated in yellowish white by the same liquor. 



6. Alcohol forms a white deposit, which is flaky and very 

 light. 



7. Heat renders the solution turbid, and occasions a se- 

 paration of white concrete flake-;. 



8. The solution of sulphate of lime undergoes no change 

 from the infusion of pollen. 



9. The oxalate of ammonia instantly produces a pulve- 

 rulent precipitate, which has all the properties of the oxalate 

 of lime. 



These experiments show that the pollen of the date tree 

 contains a free acid ; that this acid, very soluble in water, is 

 accompanied by a calcareous salt, which, being insoluble of 

 itself, is only dissolved by the intermedium in question, 

 and that this calcareous salt is the cause of the precipitation 

 of the solution of the nitrates of mercury and silver, bv the 

 infusion of the fecundating dust. 



§ III. JVasliing of tlie Pollen with cold Ifaler. 



The most sensible and the most remarkable matter in 

 the pollen being the acid exhibited upon the first experi- 

 ments, we endeavoured to obtain it separatelv, in order to 

 ascertain the nature of it. For this purpose, ue washed 

 124 grammes of pollen (about four ounces) with a suflicicnt 

 quantity of cold distilled water. 'J'he washiny;s had a red- 

 dish colour, and an acididated taste and smell similar to that 

 of beer. 



By evaporation, this liquor gave a matter of a reddish 



brown colour, the consislcnce and smell of which were like 



D 3 njoliissfs : 



