84 EFFECTS ON VEGETABLE JUICES. 



'fltmTaVKX) YH 



gas remains, as proved by Scheele. Oxide of copper, similarly 

 treated by M. Bertholet, was reduced, one part of the hydrogen 

 of ammonia combined with the oxygen of the oxide, and 

 produced water, and the azote was disengaged in the state of 

 gas, the analysis of ammonia by Bertholet, 121 azote, and 29 



hydrogen, Mem. Pav., 1785. By Dr. Austin, 121 azote, 32 



i i iyu'1 rn itroo ,1') atxjff 



hydrogen* Phil. Irans., 1788. 



OF NITROUS ACID. 



IF oxygen gas is mixed with nitrous gas a quantity of red 

 fumes appear, which are nitrous acid. 



Nitrous acid is of a brown or red color from the combination 

 of azotic and oxyginating rays ; when to this acid, concentrated, 

 a fourth part by weight of water is added, the color is changed 

 from red to a fine green, occasioned by the excess of the 

 hydroginating ray in union with the azote and oxygen in their 

 then existing proportions. Priestley has observed, that water 

 impregnated with nitrous acid, in a state of vapour, first 

 became line, then green, and ultimately yellow and this 

 proves the azotic ray became predominant, and caused the 

 change. 



t 



When a solution of the juice of red cabbage is made in 

 warm water, it is of a dark purplish-blue color. It contains 

 oxygen and hydrogen, which are in a measure neutralized, 

 and carbon, which is evidently predominant in coloring prin- 

 ciple. When you add to a wine glass of this liquid a few 

 drops of a solution of either potash, or soda, or ammonia, the 

 color is changed to a green, proving the combination of the 

 azote, of the alkali with the carbon, and hydrogen of the vege- 

 table solution. 



When to this you add a few drops of any of the acids, 





