ART. XII.--On the Double Halides of Arsenic with Casium and Rubidium; and on some Compounds of Arsenious Oxide with the Halides of Caesium, Rubidium and Potassium: Method of Analysis. The Double Halides

No compounds of arsenious halides, with alkaline halides, have been definitely described. Nickles* in his work on the bromides and iodides of arsenic, antimony and bismuth, states that these salts combine with alkaline bromides and iodides respectively, but in the case of arsenic he gives no analyses of the compounds which he obtained and he does not describe the methods that he used in preparing them. He does not even state with what alkaline halides he performed his experiments.