M. Gay-Lussac on the Action of Potash 07i Organic Matter. 367 



verted equally with the first ; from which it would appear, 

 that any number of flames might by this means be directed by 

 a single blast. 



Tile action of the one flame in directing the others may be 

 strikingly exemplified by removing the flame in immediate 

 contact with the blowpipe during the blast; for the rest will 

 be then affected only by an irregular unsteady motion. In 

 like manner, if we fuse a small piece of metallic tin or lead in 

 the reducing part of the remote flame, and then remove that 

 flame, the metal will instantly be converted into an oxide. 



By inserting the above in the Philosophical Magazine and 

 Annals of Philosophy, you will oblige yours, &c. 



Belfast, Oct. 5, 1829. ThOMAS ANDREWS. 



LVIII. On the Action of Potash oti Organic Matter. By 

 M. Gay-Lussac*. 



IV/T VAUQUELIN found, on treating pectic acid with pot- 

 -'--■- • ash in a crucible, that it was converted into oxalate 

 of potash. This experiment suggested to me the idea of 

 submittinfj liffneous matter to similar treatment. Five gr. of 

 cotton were put into a platina crucible with 25 gr. of potash, 

 and a little water. The crucible was moderately heated with a 

 spirit-lamp, and much below redness. The cotton resisted 

 for some time the action of the potash, but it eventually soft- 

 ened ; the mixture swelled without carbonizing, and the action 

 of the alkali upon the ligneous matter was discoverable by the 

 disengagement of hydrogen. During the swelling the mixture 

 ought to be continually stirred. VVhen it becomes thick, the 

 mass is dissolved in water, and slightly supersaturated with 

 nitric acid ; it then gives an abundant precipitate with nitrate 

 of lead, which, treated with sulphuretted hydrogen, produces 

 very fine crystals of oxalic acid. With nitrate of lime, a bulky 

 precipitate of oxalate of lime is obtained. Sawdust similarly 

 treated gave the same results. Sugar mixed with four or five 

 times its weight of potash, became at first brown ; but after- 

 wards white, and it yielded much oxalic acid. Starch forms 

 a very glutinous mass, and remains long in that state. The 

 addition of a fresh quantity of potash occasions li{|uefaction ; 

 the mixture swells and is converted into oxalate of potash : 

 gum and sugar oi'milk are also converted into oxalic acid, with 

 the evolution of hydrogen gas. 



One of the most singular of these conversions into oxalic 



* From Annates de C/timie, Aug. 1829. 



acid, 



