WATER. 215 



Deutoxide of Hydrogen. 



1 . HISTORY. Until 1818, water was believed to be the only com- 

 pound of hydrogen and oxygen ; but in that year, Thenard published 

 in the Transactions of the Academy of Sciences of Paris,* an ac- 

 count of this singular substance, and hitherto little has been added 

 to the facts stated in the original memoirs by this celebrated chemist. 



2. PREPARATION. f From the peroxide of barium, by the action 

 of diluted muriatic acid, and then of sulphuric acid, both, a number 

 of times repeated ; followed by that of sulphate of silver, and then by 



* Thenard's Chem. 4th Ed. Vol. V, p. 41. 



t The principal steps of this complicated process, which the student will not be ex- 

 pected fully to understand until farther advanced, are as follows : 



1. Prepare nitrate of baryta ; this may be done by decomposing the sulphate ot 

 barytes by igniting it with charcoal, by which it is turned into a sulphuret; this is 

 decomposed even in an iron vessel by nitric acid, and any iron that is taken up is 

 precipitated by baryta, and the nitrate of baryta is then crystallized. 



2. The nitrate is decomposed by ignition in a porcelain retort ; (if the heated ni- 

 trate be withdrawn from the fire in proper time, it will be left in the state of a fine 

 deutoxide, but*) it is commonly oxygenized by passing the dry pure oxygen gas over 

 the ignited baryta contained in a luted glass tube ; the oxygen is rapidly absorbed, 

 and we obtain the deutoxide or peroxide of barium ; it is this very portion of oxygen 

 thus absorbed, which is to be transferred to water or rather to its hydrogen, and it is 

 done in the following manner. 



3. Take water, six or seven ounces, and strong muriatic acid sufficient to dissolve 

 230 grains of baryta, and add 185 grains of powdered peroxide of barium ; the so- 

 lution is without effervescence, because, although the acid combines only with the 

 protoxide, the excess of oxygen is not disengaged, but unites to the water or to the 

 hydrogen of the water ; the water thus becomes oxygenized, but in too small a pro- 

 portion to be observed. 



4. Sulphuric acid is now added, just enough to precipitate the barytes, and the muri- 

 atic acid is thus liberated, and is again ready to act upon more of the peroxide, which, 

 as before, is now added in the proportion of 185 grains; this is dissolved; the excess 

 of oxygen is added to the water ; the barytes is again precipitated by sulphuric acid, 

 and the insoluble sulphate is separated by the filter ; thus the process is repeated a 

 sufficient number of times, until about three ounces of the peroxide have been em- 

 ployed, when the liquid will contain from twenty five to thirty times its volume of 

 oxygen gas. 



5. The solution is now a mixture of muriate of baryta with oxygenized water, and 

 to remove the salt, its acid is first separated by sulphate of silver, which forms mu- 

 riate of silver, and liberates the sulphuric acid, which, in its turn, is removed by so- 

 lid baryta in powder and by filtration. 



6. The solution is now the oxygenized water, or, as it is more properly called, the 

 peroxide of hydrogen, but still containing more water than is necessary for its solu- 

 tion ; this is removed by the air pump ; the vessel containing the peroxide of hydro- 

 gen is placed in another about two thirds full of sulphuric acid, and the vacuum is 

 formed over it, which occasions the evaporation of the water, and leaves eventually 

 nothing but the peroxide, which, if continued in the vacuum, is finally, but very 

 slowly volatilized unchanged. Thenard says, " au bout de deux jours la liqueur 

 contiendra peut-etre deux cent cinquante fois son volume d' oxygene." The per- 

 oxide, as thus obtained, has the specific gravity of 1.452, and it did not grow any 

 denser by continued exposure to the vacuum, although it diminished considerably 

 in quantity. 



Minute as this abridged statement may appear, there are many details necessary 

 to success, for which recourse must be had to Thenard's own account in his Chem- 

 istry, or in the Ann. de Chim. et de Phys. Veils. VIII, IX and X ; or Ann. of Phil. 

 Vols. XIII and XIV. 



* The clause in parenthesis communicated by Dr, J. Torrey. 



