Chemistry and Physics. 399 



raised ; when carbon dioxide is set free and may be collected for 

 use. The calcium plumbate is then regenerated by means of a 

 current of air. Peitz has modified this process by decomposing 

 the plumbate by a current of pure carbon dioxide at a red heat. 

 Kassner claims for his plumbate process as advantages over the 

 Brin barium oxide process 1st, obtaining pure carbon dioxide as 

 a by-product; 2d, the use of low temperatures and consequent 

 saving in fuel and in wear and tear of the retorts. — Chemische 

 Zeitwig, xvii, 1242; J. Chem. Soc, lxvi, ii, 89, March, 1894. 



G. F. B. 



4. On the Base-forming Function of Iodine. — Thus far iodine 

 has been classed solely as a negative or acid forming element. 

 But V. Meyek and Haktmann have now shown that it is capable 

 of acting to form basic compounds, and so is analogous in this 

 respect to nitrogea. In fact trivalent iodine can form a powerful 

 base resembling ammonia and which forms well defined salts with 



acids. This base is constituted thus : 1^— H being in its structure 



H 

 similar to hydroxylamine N— H . The new substances pre- 

 pared by the authors are derivatives of this simple form and have 



CsS-5 J^sH-S 



the constitution I — -C 6 H4 I and I — C 6 H 5 . Meyer was led to suspect 



this property of iodine from the fact that the group 10 seems to 

 give basic properties to the compounds in which it occurs, iodoso- 

 benzoic acid for example C 6 H 4 (IO)(COOH) being a much weaker 

 acid than iodo-benzoic acid C 6 H 4 I(COOH). It would appear 

 therefore that H. I: O, though called hypoiodous acid, will when 

 isolated be found to be a base. The first new iodine base was 

 produced from iodosobenzene C 6 H 6 IO, which itself forms salts 

 with acids. By dissolving this substance in the calculated quan- 

 tity of strongly cooled concentrated sulphuric acid, the solution 

 becomes brown and contains only the sulphate of the new base. 

 On diluting by adding ice and treating with potassium or sodium 

 chloride, bromide or iodide, the halogen salt of the new base is 

 precipitated ; this base resembling closely in this respect the 

 metals silver, lead and thallium. From the precipitated iodide 

 thus obtained the free base is obtained by treatment with moist 

 silver oxide. Its solution reacts strongly alkaline, and on evapo- 

 ration yields a gummy mass. The empirical formula of the iodide 

 is C 4 H 3 I ; but as it decomposes on dry distillation completely into 

 mono- and di-iodobenzene, its molecular formula must be C 10 H 9 I 3 , 

 and the formula of the base C 12 H 9 I 2 . OH. The chloride is a 

 white curdy precipitate much resembling silver chloride, but 

 crystallizing from warm acetic acid. The bromide is a pale yel- 

 low precipitate, similar to silver bromide, fusing at 16V°-8°. 

 The nitrate is precipited by nitric acid from the sulphuric acid 

 solution as a white mass, soluble in hot water. 



