TITHONIZED CHLORINE. 



CHAPTER XVII. 



ON TITHONIZED CHLORINE. 



CONTENTS : Description of the Experiment. The Change in the Chlorine is not 

 Transient. There are two Stages in the Phenomenon. Rays are absorbed in 

 producing this Change. It is the Indigo Ray which is absorbed. The Action is 

 positive from End to End of the Spectrum. The Indigo Ray forms Muriatic Acid, 

 as well as produces the Preliminary Tithonization. Clmnge in other Elementary 

 Bodies. Verification of the preceding Results with the Tithonometer. 



(From the London, Edinburgh, and Dublin Philosophical Magazine for July, 1844.) 



896. CHLORINE gas, which has been exposed to the daylight or to sunshine, possesses 

 qualities which are not possessed by chlorine which has been made in the dark. 



897. This is shown by the circumstance that chlorine which has been exposed to 

 the sunshine has obtained from that exposure the property of speedily uniting with hy- 

 drogen gas ; a property not possessed by chlorine which has been made and kept in 

 the dark. 



898. This quality gained by the chlorine arises from its having absorbed tithonic 

 rays corresponding in refrangibility to the indigo. It is not a transient, but apparently 

 a permanent property, the rays so absorbed becoming latent, and the effect lasting for 

 an unknown period of time. The facts which I shall proceed to describe will be in- 

 teresting to chemists, because they plainly lead us to suspect that the descriptions we 

 have of the properties of all elementary and compound bodies are either inaccurate or 

 confused. These properties are such as bodies exhibit after they have been exposed 

 to the light ; we still require to know what are the properties they possess before ex- 

 posure to such influences. 



899. Natural philosophers will also find an interest in these phenomena, for they 

 finally establish for the tithonic rays two important facts : 1st, that those rays are ab- 

 sorbed by ponderable bodies ; and, 2d, that they become latent after the manner of heat 

 Some years ago I endeavoured to prove that these things held for a compound sub- 

 stance the iodide of silver (Phil. Mag., Sept., 1841). 



900. For reasons which will be obvious as the description proceeds, I shall speak 

 of chlorine which has been exposed to the beams of the sun as tithonized chlorine. 



I. Description of the Experiment. 



901. In two similar white glass tubes place equal volumes of chlorine, which has 

 been made from peroxide of manganese and muriatic acid by lamplight, and carefully 

 screened from access of daylight. Expose one of the tubes to the full sunbeams for 

 some minutes, or, if the light be feeble, for a quarter of an hour : the chlorine which is 

 in it becomes tithonized. Keep the other tube during this time carefully in a dark 

 place ; and now, by lamplight, add to both equal volumes of hydrogen gas. These 



