I n tlic r l n n d o , der Chemii' m i d p/uwin/v;(~ for 1866, (vol. Ixxv p. 203), IIugo Schiff has described, Tinder thc name of aarylureid, a coritlensation product formed hy the union o f t w o molecules of urea with one of acrolein, in accordance with the reaction:
JYithout being aware of Schiff's labors, and whilst studying the aldehyde compounds with quite iliffercrit objects than those followed by Schiff, I obtained t h e same compound, but had assigned to it a quite difiereiit formula. The explanation of ihesc cliffcrcnces hecornes apl)arcnt on studying the nirtliotl b y which ScliifT prepared t h e eompoiiiid, since this methot1 did r i o t and coilid not yield the substaiiec i n quebtion. IIe mixetl a conccntr:lttd aqueous uolution of urea with acrolein, and after l i i ~aerylurcicl hail gradually precipitated as small while needles (?), hc washed it merely with ether and water, and dried in U Q C Z I O . IIe likewise states that powdered
59
ACROLEIN-UBEA.
urea unites with acrolein directly. u T h e mixture swells up, and is converted into a wliite brittle mass, which in some places has an entirely crystalline appearance. B y far the greatest portion is intimately mixed with a white porcelain-like product, formed by decomposition of the acrolein.” The analysis of this body gave, as might readily have been expected, no satisfactory results. Schiff further states t h a t in various preparations, some of which were prepared at ordinary and others a t higher temperatures, he obtained carbon varyihg between 41 and 47 per cent., and hydrogen between 6.9 arid 7.1 per cciit. The formnlx of diacryltriiirrid requires 42.3per cent. carbon and 6.3 per omit. hydrogen. Tliat of ncryldiureicl, which Schiff adnpted, but 38 per cent. c‘irlmn and 6.3 per cent. hydrogen. Throughoiit his investigation Schiff worked upon impure substances, and in that way obtained not only varying results, b u t resultv which would support no rational formiila, the one which h e finally adopted,-that of diacryltriureid, being altogether erroneous. In the first expwiriient made by tile author, the acrolein obtained b y heating anhytlroub glycerin with potassic bisulpliate was allowed to distil over directly into an alcoholic solution of urea. A precipitate formed a t once, and after a time a coiisideralle amount was obtained,the urea however h i n g still in excess. The filtrate w a s of a reddish eolor, and on evaporation yielded a resinous or gummy mass, which could neither be sublimed or crystallized from solvents. T h e precipitate left 011the filter was of a yellow-white color, b u t after repeated treatment with alcohol became quite white, and lost all of the gummy or thick oily substance a t tirst adhering t o it. I t s analysis showed that it had been formed by the union, not of two, but of one molecule of urea, with one of acrolein, n molecule of water being eliminated, and the resulting compound having the formula C,H,N,O or CO (NII)PC,H,. Carbon Hydrogen
Found. 49.01 8.3
Theory. 48.98 6.12
Not only as originally prepared by repeated purification with alcohol, but also after treatment with carbon disulphide, chloroform and ether, in all of which it is only slightly soluble. every attempt t o obtain it in a crystallized condition was unsuccessful. It did not melt nor sublime, and when strongly heated underwent decom-
60
A C R O L E I N - UREA.
position. It war rcatlily ;Ittractect by nitric acid, Imt tlie product8 of the tlecomposition were not stitdied. F r o m its soliition ill alcohol no precipitate was obtained on the addition of brorniiie. On treatnneiit with hydrochloric, tartaric ;iiirl acetic :iuids 110 $:iltH were formed. The alcoholic extracls were collected, and yielded, after siiccessive solutions in alcohol and precipitatioii with mater, a white substance similar t o that above described, and having a melting-point of 185". Since sufficient of this nxtterinl coiild not be obtained to adniit of its satisfactory purification and analysis, a much larger amount of urea i n alcoliolic solution than tliat used in the foregoiug experiments (40 griiis.) \vns treated with acrolein in successive portions in ;Iclosed vessel, until xfter l o n g continued warming tlic odor of acrolein ceased to d i s a p p w . Iii this case, unlike tlie forrgoiiig, no precipitate \vas formed, iior did a n y take place until after the addition of water, wlicn a very nbunclaiit white anioq~lioiissul)st:ince waR t h r o ~ v nIlo\vii. This w a s boiled with iilcoliol ;t grew iiiaiiy tinies, each cutixct :tfYorcling :L white: 1)rwipit:itc \rlieii diluted with water, : ~ n dtlic portiori of ~ , I I I ' ( ~ni:itc~rial obtaiiir'tl c~veiitiinllywas not inoro tliaii t1i:it 1)rociirwl i n t l i c . tii*st iiist:iiice, wlieii 1)ut a small . amount of urea was used and tlie aci.oicSiii wab iiot ;ultlrd in ( J X ( : C ' ~ Sl'lie \V:IS (IO. ( S I I ) ? . Il,, coiri1)osition of the subst,aneci thus 01~t:iin~iI and it was idtmtical i i i all rc1sl)ccts \\.it11 tlie \ill)st;iiictl i'oi-incd in tlic first c'asc. From the : i l w l i o l i c [axtraiats i i i I o t 1 i t . i . 5iil)st;Liice could be obtained, nntl tlie c?spl:uintioii of I > 1 i 1 : ~ 1 1 yi('li1 of the lj~ t o be pure acrolciii-uiw i i i thc w(.oiiil ['XN., \v:i.. c'\ ~ ~ i i t i i : i I foimd due to tho presciicc of tlie oil!- or g i i i i i i i y sitbstaiicc~,f'oniied as a byproduct. 'I'lic nniouiit o f t l i i h l)>--i)i,oiliict\vas app:irerit,ly iniich greatcr i l l t l i r ~sccontl caw, :hilt1 c ~ x l ~ l a i i i ethe d iion-l)rec,ipitiition of the acrolc4ii-iii.ca until :iftc.i. t l i c ~ :itlditiori o f watcr t,o the original solution of tlic. iirea i n nlcoiiol. Aiitl tliv tvn:ic:ity with which it xdhered to tlic ac~olcii~-rirea o i i 1)rw~il)it:~t i o i i wit11 water, ancl c:arrietl it. i n t o sulritiori :igniii on c:icli + \ I C lioiliiig with :ilcolio.l, explains the vcry stn:tlI eveiitu:il yielil o f t l i v 1 ) i i i ' c ninteri:il. It w a s also due to t h e sinall atllicrent t i w e s o f tlii.: oil, that the secvncl body, tlic oiie soluble i n al(:oliol, h : d :L i i i c ' l l iiig l l o i i i t of 18.io, : i i d w:is supposed to be s oine t 11i I Ig (!I w t 11%I I t 11 e nc. 1 ~I c,i ) i 1- II re a. I he prcw~iiceof this oil, \vliic:h I w:zs iiinablc to isohtc, explains at1 the above clifficiiltics :Lilt1 til(> c'im)iieoii* r('siiltP ol)t.xiiic(l by Schiff. Iri coiiclusion, it ni:ip 1)c u:tl'c>ly stated that h i d e s the srnall am oiiiit of this oily by-product, tlic orily coiiipoiind formled hy the 1113
, i r ( k
7
,
61
EARTHY FZHKIC SULPIidTI.: PROM ARK AKSAS.
action of acrolein on urea, was that containing .he residue from one molecule of urea, the compound CO.(NH),. C3114,
XIII. NOTE ON AN E A R T H Y F E R R I C SULPHATE FROM ARKANSAS.
BY CHAS.E. WAIT. Several weeks ago a sample of earth was serit to me for examination, from Southern Arkansas. It is a friable, yellowish substance, partly soluble in water, streak uncolored, taste astringent. Upon analysis I find i t contains the following : Insoluble in cold w a t e r . . ..................... Soluble in cold water ........................
PER CENT.
12.61 87.39
100,00 The soluble portion consists of Fe, 0, ..................................... 21.82 SO, 33.81 H,O ........................................ 31.76
..........................................
87.39 By assuming the following arrangement, F e z 0 , . ..................................... 2 1 . 8 2 SO, ......................................... 33.81 I1 ,O combined, .............................. 22.41 1-1, 0 hygroscopic. ............................ 9 . 3 5 87.39 we are able to deduce a formula consistent with that of the native persrilphate of iron, viz.: Fez (SO,), (H,O),. If all the water be considered as belonging to the compound, the formula will be Fez (SO,), (IIzO),3. It is said an unlimited snpply of this substance may be obtained.
