194 REPORT—1904. 
found in Butlerow’s paper ‘Ueber Isodibutylen,’’ a paper which is 
remarkable in that it anticipated by a quarter of a century the views that 
are generally held at the present day. Butlerow’s experiments showed 
that in presence of sulphuric acid equilibrium is established between the 
two olefines and the two isomeric alcohols formulated below, so that on 
oxidising with chromic acid products were obtained characteristic of each 
of these four substances :— 
CH, eis 01 2 ik 0: ip Mey bss ay 91 CH, CH, CH, 
goa’ 4 sf, a vA a Sit 
CH C C(OHS C 
| sree dine sls encaros bas ate es ecgegy 
CH, ersgoeiicaeh 6) canada 6s: esiaietiemebeleieags 2 
| | | i 
CMe, CMe, CMe, CMe, 
In no previous case had the existence of a reversible isomeric change been 
demonstrated, and Butlerow fully realised the importance of his discovery. 
At the end of his paper he suggested that a similar equilibrium between 
isomers might exist even in the absence of any special catalytic agent and 
that this would account for the formation of isomeric ethers from prussic acid 
GHC. iNet BE GoM eet Bs 8 5 ioe CsH,.N 36 : 
— __~_ 
ethyl cyanide prussic acid ethyl isocyanide 
and for a number of other abnormal changes. 
Subsequent investigations have fully demonstrated the correctness of 
Butlerow’s theory since reversible isomeric changes have been found to 
be of frequent occurrence, especially amongst the ketones and nitro- 
compounds. 
Isomeric change not spontaneous.—The only important modification of 
Butlerow’s theory that has taken place depends on the proof that has 
recently been given? that even the most easily convertible compounds 
do not change spontaneously but that in all cases a catalytic agent is 
necessary for the establishment of equilibrium. The necessity for a 
third substance in order to bring about chemical change has been per- 
sistently advocated by Armstrong and has been demonstrated experi- 
mentally by Dixon, Baker and others in the combustion of carbon 
monoxide and phosphorus, and in the union of hydrogen with oxygen 
and with chlorine. Baker has further demonstrated the remarkable fact 
that moisture is necessary not only for the (apparently direct) union of 
ammonia and hydrogen chloride, but also for the dissociation of ammonium 
chloride, which cannot be decomposed by heat alone. Recent observations 
have extended the proof to the reversible isomeric change of nitro- 
camphor and £-bromonitrocamphor and it has been found that even the 
transference of a mobile hydrogen atom cannot take place within the 
molecule, but is dependent on the formation of a complex molecular circuit. 
It is therefore impossible to maintain any longer a distinction between 
those isomerides which are only convertible in presence of a specially 
added catalytic agent and those which find in the ordinary dirt of the 
laboratory the catalytic agent that they need and which therefore appear 
to change spontaneously. 
1 Ann. 1877, 189, 44. 2 Lowry, Zrans. 1899, 75, 219. 
