Intelligence and Miscellaneous Articles. 223 



flame, the closer investigation of which led to the conclusion that 

 during the combustion of oxygen and hydrogen, under certain cir- 

 cumstances, peroxide of hydrogen is also produced. As this sub- 

 ject has not, to my knowledge, yet been thoroughly discussed, I 

 will briefly communicate the experimental results which up to the 

 present time I have obtained. 



As previous experiments had already indicated that the blue 

 flame is conditioned by accidental circumstances, I sought before 

 all things to ascertain these. It then appeared that the flame is 

 not visible when hydrogen burns in oxygen, but only on the com- 

 bustion of oxygen in hydrogen, provided that both are free from 

 atmospheric air, — and, further, that it comes out better when to 

 one of the gases a little sulphurous acid is added, while it disap- 

 pears if the gases are passed over potassium hydrate. In conse- 

 quence of this I removed the sulphuric acid (from which the gases 

 appear to have taken up a trace of sulphurous acid) from the gas- 

 holder. The blue flame was now no longer visible ; but it immedi- 

 ately became so after the addition of sulphurous acid. The different 

 experiments all led to concordant results, whether a smaller or a 

 larger combustion- space (from 5 to 500 cub. centim.), or gases pro- 

 duced by electrolysis or otherwise were employed. All this shows 

 that the blue flame stands in connexion with the sulphurous acid 

 contained in the gases. 



During these experiments the water formed each time was also 

 examined. A trace of sulphuric acid was found in it as often as 

 the blue flame was visible, which was absent whenever the latter 

 did not appear. Besides this, the water usually took up some per- 

 oxide of hydrogen, which was proved by iodide-of-zinc starch and 

 sulphate of iron, by permanganate of potassium, and by the so- 

 called perchromic-acid reaction. 



These in themselves interesting facts formed the subject of 

 further experiments. First of all I convinced myself that, under 

 certain conditions, H 2 2 is produced both when H burns in and 

 when burns in H, but that the amount differs very much, ac- 

 cording to the conditions of the experiments. Of essential import- 

 ance is the velocity with which the burning gas penetrates that 

 which surrounds the flame : if this velocity is very inconsiderable, 

 traces only of H 2 0, appear, while -with considerable excess of pres- 

 sure striking reactions are obtained. Thus, in one case, during 

 the combustion of oxygen in hydrogen at the temperature of the 

 room, I obtained water containing 0'0008 gram H„ O,, in 1 gram, 

 therefore nearly 0-001 of the whole ; and it appears to me very 

 probable that under more favourable conditions considerably more 

 might be produced. The presence of S0 2 , while, on the one hand, 

 it conditions the blue flame, diminishes the amount or prevents the 

 occurrence of peroxide of hydrogen ; at the same time the corre- 

 sponding amount of sulphurous is converted into sulphuric acid. 

 These, as well as other experimental results, indicate that the blue 

 light has its origin in the combination of H.,0 o and SO to form 

 H.SCX. 



