1119 
Evidently light markedly accelerates the action of iodine on nitrite 
solutions. 
It has also been observed that in presence of light the action of 
iodine on hydrazine hydrochloride and hydroxylamine hydrochloride, 
is decidedly more rapid than in darkness. (See table p. 1118.) 
The oxidation of hypophosphorous acid by Iodine has been inves- 
tigated by various workers. Rupp and Finck (Arch. Pharm. 1902, 
240, 663) propose for ‘the estimation of hypophosphorous acid a 
method which is based on the fact that in acid solution the hypo- 
phosphorous acid is oxidized to phosphorous acid. Srer.e (Trans. 
Hypophosphorous acid and iodine. At 28°. 
Quality of light Time of Amount of | Unchanged 
| reaction liodine added| iodine Volume of solution 
HOC: a (factor 0.852) 
1) Sunlight | 150’ 0.03175 0.02475 
| | hypophosphorous acid 
Darkness | 150’ | Do 0.02934 Vienne: 
and *2:5' ic; 10 iodine. 
\ 
2) Sunlight 250 Do 0.01396 
Do 
Darkness 250’ Do | 0.01612 | 
3) Diffused light | 160’ Do ___0.02689 | 
| Do 
Darkness 160’ Do | 0.02912 
4) Diffused light | 260’ Do 0.01425 
Do 
Darkness | 260’ Do | 0.01587 
Sodium hypophospnite and iodine. At 28°. 
| N salt soluti 
1) Sunlight 140’ 0.03175 GvOtosss eee AO es ROLL E 
(factor 0.984) and 2.5 c.c. 
Darkness | 140’ Do 0.01385 mp 
| 10 iodine. 
N 
2) Sunlight 240/ Do 0.00268 (75 ee. 75 (factor 0.984) 
Darkness 240’ Do 0.00360 |ana HE ee iodine. 
N 
3) Diffused light | 150’ Do 0.01175 (50 ee. 79 (factor 0.984) 
Darkness 150’ Do 0.01378. | |and DINE Wy iodine. 
| N 
4) Diffused light 245’ Do | 0.00308 | \75 cc. 75 (factor 0.984) 
Darkness 245’ Do | 0.00356 [and 25 ce. a jodine, 
