Chemistry and Physics. 413 
CH[CH(CH,),] | 
OH whose bromine derivative gives isopropylacetyl- 
e by the ie of alcoholic potash; and methylethylethylene 
cH [CH(C.H P JERRY sOUny: 
cu, which does not yield valerylene under these cir- 
cumsta ances, but is transformed into valeric ether. Isopropylacet- 
ylene boils at 35°, forms a crystalline addition product with silver 
nitrate AgC=C — CH | On , which is decomposed by iodine, yield- 
ing IC=C— —CHY OH » moniodisopropylacetylene. — Bull. Soe. 
Ch., Ul, xxviii, Aug., 1877. « BB 
5. On the Co ies ta of unsaturated Dibasic Peers —At the 
' Close of a series of researches 5 certain unsaturated dibasic 
acids made in his tabarston TTIG sums up the results and dis- 
cusses their bearing upon the sunceeiians of the acids in question ; 
i. e., fumaric and maleic acids in one group, and itaconic, citraconic 
‘ and mesaconic acids in another. The facts are (1) the two former 
unite directly with hydrogen to yield succinic acid OH,.C . oon’ 
as the three latter by the same treatment yield the same pyrotar- 
On, 
taric acid, cH . COOH ; (2) the former acids by union with bromine 
H,.CO 
give two different sete ae acids (both of which, however, 
an isomer; (4) while mono- or di-bro m-citraconi¢ mht mesaconic 
re m an 
and yield no carbon dioxide when thus treated; (5) while fuma- 
rates and maleates yield on Sigg th den the same acetylene, and 
citraconic and mesaconic acids the same allylene, itaconic "acid 
gives a hydrocarbon not precipitating silver solutions. There is 
no constitutional formula which will satisfy all these conditions if 
the position be maintained that in pores yde ompéunds se 
carbon atoms are always united by several bonds. Hence the 
Promina a in which there are single carbon atoms eo eg Meena 
are not completely balanced. Rejecting also as unproved the 
xistence in a compound of carbon atoms three of whose units are 
