FLUORIC ACID ITf WAVEILITE. 267 



is precipitated in fine powder, pour off the clear lime-water 

 for use, at the time it is wanted. 



Put the feathers to be cleaned in. another tub, and add to 

 them a quantity of the clear lime-water, sufficient to cover the 

 feathers about three inches, when well immersed and stirred 

 about therein. 



The feathers, when thoroughly moistened, will sink down 

 and should remain in the lime-water three or four days, after 

 wliich the foul liquor should be separated from the feathers by 

 laying them on a sieve. 



The feathers should be afterwards well washed in clean water 

 and dried upon nets ; the meshes about the fineness of cabbage^ 

 nets. 



The feathers must from time to time be shaken upon the 

 nets, and as they dry will fall through the meshes, and are to 

 be collected for use. 



The admission of air will be serviceable in the drying; the 

 whole process will be completed in about three weeks ; after 

 being prepared as above mentioned, they will only require 

 beating for use. 



XVI. 



Note from H. Davy, Esq. F. R. 5., SfC. SfC, on the Fluoric 

 Acid in Wavellite. 



To Mr. NICHOLSON, 



Dear Sir, Killarney, Ireland, June 15. 



X SHALL feel much obliged to you, if amongst the articles Fluoric aeid ia 

 of intelligence in your Philosophical Journal, you would men- wavellite. 

 tion that I have found the acid which exists in minute quanti- 

 ty in the wavellite (the new fossile fi'ora Barnstable) to be the 

 ^uoric acid, in such a peculiar state of combination as not 

 to be rendered sensible by sulphuric acid. 

 I am, Dear Sir, 

 with great respect, 



Your obedient servant, 

 H.DAVY. 

 W. Nicholson, Esq. 



M m 2 ^^^"" 



