Proceedings of the British Association. 237 



on a prism of Munich glass ; the spectrum thus formed was passed 

 through the gaseous medium under examination, and the resulting 

 effect observed by a telescope. It was found that the dark lines of 

 the spectrum materially changed their positions as different colour- 

 less gases were used ; and that, by subjecting the spectrum to the 

 absorptive influences of chlorine, nitrous acid vapour, the vapours of 

 iodine, bromine, &c, numerous dark, and some luminous bands not 

 previously observed, were brought into view. The spectra produced 

 by coloured flames was also examined, and many curious conditions 

 observed. Dr. Miller had sought to ascertain if any relation could be 

 found between the chemical characters of the bodies under examina- 

 tion and their properties of exhibiting Fraunhofer's lines ; but as yet 

 no such relation could be detected. 



* Recent Experiments on Ozone,' by Prof. Schonbein. — Prof. 

 Schonbein was first induced to undertake his researches from the ob- 

 scurity which rested upon the phenomena of the odour produced 

 during the galvanic decomposition of water, resembling the smell of 

 an electrical machine, and during thunder storms. In pursuing 

 these researches, the author was led to the discovery, that the smell 

 was always developed at the positive pole ; that it was capable of be- 

 ing preserved in closed bottles ; that heat destroyed it, and that many 

 of the metals had also the same power. Experiments were made 

 with a view to discover some means of procuring ozone easily ; and 

 after the trial of a great many bodies, it was found that phosphorus 

 was particularly suited for the purpose. If a piece of phosphorus is 

 placed in a bottle of common air, when maintained in a moist state, 

 it readily produces this peculiar principle, on which the electrical 

 smell depends. Several experiments were shown to illustrate the 

 effects of ozone in bleaching litmus paper and paper coloured with 

 indigo, or a solution of that substance. If powdered iron or silver are 

 placed in vessels containing ozone, the smell is immediately removed., 

 and the metals exhibit a kind of oxydation. Other bodies were named 

 as producing a similar result; and many chemical decompositions were 

 found to arise from exposure to the action of this peculiar principle. 

 Solution of iodide of potassium is rapidly decomposed, iodine being 

 set free ; this was shown by a mixture of this salt with starch, which, 

 on being exposed to the action of ozone, turned blue by the formation 



