( 42 ) 
It has been assumed by me in the above that the ordinary shape 
of VAN PER Waals’ equation of state remains also valid when the 
substance assumes the “solid” state in consequence of other molecular 
groupings. I do not shut my eyes to the fact that there are still 
some difficulties left, particularly with respect to the special forces 
which possibly come into play, and which possibly may modify the 
figure given by me in some respects; but I yet believe that through 
my considerations at least some insight is gained into the origin of 
the third (solid) phase, enclosed in the equation of state in its 
ordinary shape, when the association of the molecules is taken into 
account and the variation of volume attending it. 
Chemistry. — “On a synthesis of aldehydes and indole [3].” By 
Dr. R. A. Weerman. (Communicated by Dr. W. A. van Dorp). 
(Communicated in the meeting of April 23, 1909). 
Phenylacetaldehyde. 
In a previous communication ') a method was described for (he 
preparation of substances of the structure : 
C # H k s -C = C — N — C. 
It now appeared that by the action of acids similar compounds 
)»e aldehydes with destruction of the bond between the nitrogen 
an t e double bound carbon. In this way methyl styrylaminoformate 
generates phenylacetaldehyde. 
C.H.C h =C H — N h — c8ch,-» C.H.C h = C,“h + NH„+00,+CH.OH 
Tl c.h.c h ’_c{5. 
Ihe oxime melts at 99°—100° 
0,2115 gr. yielded 19,2 cc. N s at 759 mM. and 13° 
Found: 10,66% N 
Calculated for C 8 H,NO: 10,37% N. 
wttonitrophenylacetaldehyde . 3 ) 
-j_ aldeh yde is generated in an analogous manner from methyl 
b These Proe. 1907. 
') Compare Mohr Journ. f. Pr . C h. [2] 75, 549. 
'>0 showsthat 1 ’ pheoTr U etlHt 1 a hed arUc ' e ^ Semmier (Ber ' 42 ' 584 >- in 
there is everv ^^kcetddeliyde Can readil y P ass into the phenyivinylalcohol, 
read tautomerieallv ° j° r assum ' n & that orthonitrophenylacetaldehyde may also 
1 and m conn ection with the negative substituent, it is even 
>hd condition it possesses the vinyl alcohol structure. 
