OF ARTS AND SCIENCES. 1''" 



The behavior of this substance towards alkalies is especially charac- 

 teristic. The reaction may best be observed when banc hydrate « 

 cautiously added to a dilute alcoholic solution. An .ntense .n.hgo- 

 bL color is at once developed, which, however soon passes through 

 green to reddish yellow, with the simultaneous format.on of a brown- 

 fed, fiocculent precipitate. The same brown prectp.tate .s formed 

 wh n the muoohromylbromide is boiled in an excess of bar.c hydrate 

 but the two products which are most char.acteris«c of the decompos- 

 tion of muoobromic acid under the same conditions,* hromacetylen and 

 malonic aci.l, are formed in such small quantities that they maj-as^y 

 be overlooked. This peculiar behavior led us to suppose at fl St we 

 had not the simple bromanhydride of mucohromic ..cd u, our hands, 

 b t that an hyd'ro.yl group outside the carbo.yl bad been repla^d. 

 A more careful study showed, however, that such was not he ^se^ 

 Although this mucobromylbromide is apparently bttle affected even 

 ^y hot-water, on boiling it is gradual, ^'^^^^l^:^. 

 then contains mucobroinic aci.l (in. pt. 1/u i^' ) 

 hoi decomposes it with more difficulty ; still, after several I'ou s bod- 

 in. with reverse cooler, on evaporating the excess of alcohol and 

 c„:ii„.r strongly, crystals separated which had the charactenst.c form 

 Jthe e.hyh:.ucobroma.e,and which tnelted at 51" after recrystalhza- 



tion from alcohol. -i • i *„;i ;,^ « 



^f.rMo,nic Actankyiride. When mucobrom.c acd ts heated ma 



sealed tube for several hours with an excess of -^^^'^^^ ^ 

 or when it is heate.1 under ordinary pressure wth acct.c ■"■'' J 'l'"^*' ^ 

 Istaucc is foru..d, which is very soluble in alcohol, ether or chbr- 

 form. a„d which may be purified by prec.p.tafon by w er n U 

 alcoholic sohnion. It falls as a colorless 0,1, whah gradually sohd.hes 

 in slc.i.ler, dendritic needles, which melt at 53-54 . 



0.9015 grm. gave 0.8050 grm. CO, and 0.1290 grm. H,0. 



Calculated for C«UBr,0, . C,U,0. iT^^ 



C 24.00 ^^-^y 



H 1.33 1-^^ 



That the acetyl group enters the carboxyl in this c.ase is show„ by 

 Ae behavior of ethylmucobromate to acety ch bnde. After sev 

 eral hours' heating, with an excess of acetylchlor.de, at UO-loO , 

 r e er was fou'ud to be unaltered. T'- substance wh.ch wa. 

 obtained crystallized in the form of the c.hyl-e.her, -^Itecl at a„d 

 upon analysis proved to eon.ain t l«^;equire^^^ 



* Cf. p. 188 el seq. 



