Chemistry a 



X 



5. On Potassium triiodide.— Johnson- has succeeded in obtain- 

 ing potassium triiodide by evaporating a saturated aqueous <>r 

 aleoholic solution of iodine in potassium iodide, over 



acid. At first dark colored cubes of the iodide colored l.v iodine 

 appeared ; hut after some days, lustrous dark blue prismatic crys- 

 tals were deposited, sometimes two inches lon-\ which atibnhd 

 the composition of the tri-iodide on analysis. This substance is 

 very deliquescent, becoming a brown liquid on exposure to the air. 

 In specific gravity at 15° was 3-498. From the fact that its 

 atomic volume is 120-2. hv '■xperiment, and 1 22 "2 bv calcuhn ion 

 from the sum of the atomic volumes K+I 3 , but only 10.5 •« \ from 

 KI+I 2 , the author infers that it is an atomic and not a molecular 

 A.—J. Ch. Soc, xxxi, 249, March, 1877. g. f. e. 



6. On Ethyl-»»r<-<iptau ami it* Ik-rir.i'tire*. — In the course of 

 an extended investigation into ethyl-mercaptan and the corre- 



5 mercaptides, Claesson has made the curious observa- 

 tion that the group S.C 2 H 5 of mereaptan is readily ex- 



chaiiu* d for the haloid constituents of the fatty series, the substi- 

 tution taking place the more readily the less condensed the carbon 

 nucleus of the compound. Thus by acting on carbon tetrachl o- 

 i'ide w ith mereaptan in presence of sodium ethylate, sodium ehlo- 

 ■i : the heat evolved, and a liu'ht 

 yellow oil of 1*01 spa ed, which the author 



1 which has the formula C(S . C 2 

 H 5 ) 4 . He has prepared also dicarbonhexamercaptid. 



epared also eth; I has studied 



nd dicarbontetramercaptide C^(S._C 2 H S ) 4 ^ The author 



its properties and reactions. — J. pr. Ch'll', xv,~193, March, 1877. 



7. On the Synthesis •>/ CoHnurrin.—Tu^sixys and IIk 

 ive effected a new synthesis of coumarin. They were le< 

 ethod by observing that acetylparacumaric acid \va- «- 

 hen paroxybenzaldehyde was heated 



pected acid was produced, and from it als< 



hydro-orthocumaric (melilotic) acid. By sir 

 orthocumaric a< i 1 \\ is lee n p »>ed t ito eti> o\i b u 1 

 coumarin which was obtained s 

 The authors consider - le with the 



C 6 H 4 /CH = V H — Ber. Berk Chem. Ges., x, 283, Feb. 



