INDUSTRIAL AND ENGINEERING CHEMISTRY
846
methylunibelliferone dissolve$ in acetone. The lattcr excludes t'he mercury bands a t 3130 A. and shorter xvave length, but is substantially transparent t,o longer wave lmgths of light. The reaction rate vias reduced t o about one tenth of its former rate if the light, \vas first, passed through 1 cc. t.hick filter consisting of 1.5 5 copper ammonium sulfate dissolved in This solution practically excludes the mercury bands at 3660 A. antl shorter wave lengths, and reduces the light energy in thc viijihlc blue and violet to about,47.% of their normal value. The redvction in rate was just about twice that indicated b y the rccluc,tion i n light mergy; this suggested the possiblity t h a t the ultraviolor component of the light might, be more effective per quantum oi' energy absorbed than was the visible. Since Pyres i j very t,ransparent to the effective spectral rilgion, the reaction vessels were made of that mat,erial. The lamp \\-its a Hanovia type LL high pressure mercury-quartz arc with 12 inches of effective arc length, operated a t 1050 xvatts electrical iiiput and 1160 \Tat#ts over-all in the controls, and mounted vt'rtically. The reaction chamber n-as 2.5 cm. from the lanip cnvelope and separated from the lamp chamber by a l.0-cni. 1ayc.r of circulating Tvatcr. The water provided temperature control and, by filter action, removed unwanted infrared radiation3 from the lamp. The entire apparatus was 12.7 cm. in diamet,cr. The reaction chamber ! found necessary to u>ea n :tirtiglit cell for pH measuremrnts: Oiie gram ~i cnrbon hlnck is mixed with 50 ml. of liquid and allowed to stand in a .toppcred test tube for 24 hours at 35' C. .It the etitl of ttii. period the liquid was quickly filtered! and the ~ l u d g ew:is put iiito :in :iirtigiit cell which WIR placed in the pH meter. A Beckman Type G meter with a glass electrode was u-ed. The >ludgc \ v : v checked a t intervals until tlie readings im-:inir eon>t:Liit. This required from 15 to 30 minritw. .ill tests w w rit!) iii triplicate. The results are given in the follon-ing tahiP:
l l i r r o n e s IV-6 Furriex
4 2
Statex 03 Gastea
8.8
8.8
Btarex H
3.8
3 0
