514 report — 1878. 



nitrogen. The nitrous anhydride (N 2 3 ) and nitricoxide (N 2 2 ) are under these 

 conditions immediately oxidised by the ah- (admitted and drawn in through the air 

 holes or through the jet) into peroxide of nitrogen N 2 4 . The several reactions may 

 be combined thus : — 



N 2 2 + N 3 O s -r 30 = 2N 2 4 . 



This peroxide of nitrogen (N 2 4 ) is quickly absorbed by the spray and decom- 

 posed by it into nitric oxide and nitric acid. The nitric acid is dissolved by the 

 hot water of the spray and carried down into the reservoir at the foot of the tower. 

 The nitric oxide remains undissolved by the spray, but is oxidised as fast as pro- 

 duced by the air into peroxide, which in turn becomes split up into nitric oxide 

 and nitric acid, the latter being collected as before in the reservoir. The re-action 

 may be approximately shown thus : — 



6N 2 4 + 2H 2 = 3N 2 2 + 8HN0 3 . 



Eventually, therefore, the lower oxides of nitrogen becoming oxidised by con- 

 tact with air into the higher peroxide, and this in turn becoming absorbed by the 

 spray and divided into nitric oxide and nitric acid, which latter is always dissolved 

 and carried down, and the reactions being successively continuous, the whole of the 

 original nitric acid, when used and operated upon under these conditions, will be 

 regained. ... 



Practically the whole of these reactions occur simultaneously, so that the nitric 

 acid is reproduced from the lower oxides as soon as they are generated. 



This process places another weapon in the power of the manufacturer, and ren- 

 ders available for many purposes a re-agent at present limited in its application. 



In conclusion, I will only add that in no single instance has the process failed or 

 even varied in its results. 



7. On some Substances obtained from the Boot of the Strawberry. 

 By Dr. T. L. Phipson, F.C.S. 



The author has found in the root of the strawberry certain substances closely 

 allied with some that are contained in the cinchona barks. The principal of 

 these is called Fragarine, and can be obtained in large quantities by a process which 

 with cinchona bark yields the product called Cinchona red. There exists in the 

 strawberry root a kind of tannin, closely allied to quinotannic acid, and when 

 its solution is boiled for some time with hydrochloric acid, it decomposes into 

 glucose and fragarine, which is precipitated as a reddish brown amorphous 

 substance, highly electrical by friction, taking a reddish purple colour with alkalies, 

 yielding nitro- and chloro-compounds of a yellow colour, and a conjugated acid with 

 sulphuric acid. On being heated, fragarine yields water and is decomposed 

 without fusion, yielding much charcoal and a white sublimate, soluble in water, 

 which is, apparently, pyrocatechin ; its solution gives a green colour with salts of 

 iron. Melting potash decomposes fragarine with production of dark brown sub- 

 stances and a little protocatechuic acid, which can be isolated by ether from the 

 acidulated solution, and also colours iron salts green. 



Whilst fragarine is being produced by boiling with hydrochloric acid there 

 is diffused through the laboratory a veiy agreeable odour of essence of cedar. 

 The root also yields a product very similar to quinovic acid. 



8. On a new Mineral White Pigment. By Dr. T. L. Phipson, F.O.S. 



For many years past attempts have been made by several chemists to discover 

 some new mineral white of a less costly and less dangerous nature than white lead. 

 Very little success seems to have attended these researches until quite lately. 

 First, the oxide of zinc produced by the combustion of the metal in the air was 

 found to have certain properties which allowed it to be used as a non-poisonous 

 substitute for carbonate of lead. But its production is very costly, and its cover- 



