Se eae ee te ee eS 
C. G. Williams on Organic Substances. 327 
fluviatile beds at Amiens are an index of the current of the 
Somme, of its flood-level, and the force of its stream. e 
cannot determine the rainfall at Amiens in the Quaternary 
Period except by its results in the form of gravel-deposits; and 
these appear to give as good indications as the fall of the Mul- 
leer bridge girders does of the flood in that river. 
Arr. XXXI—On the Artificial Formation of Organic Sub- 
stances; by C. GREVILLE WiLt1aMs, Esq., F.R.S.* 
CHEMICAL researches are liable at various epochs to take 
special directions, Before 1830 organic chemistry was compar- 
atively little studied. The simplification of the methods of 
organic analysis by Liebig took place at a most opportune mo- 
ment, and gave an extraordinary impetus to the study of car- 
bon compounds. So great was this influence that proximate 
and ultimate analysis made a progress, the rapidity of which 
was unexampled in the history of science. 
_ But chemists soon became dissatisfied with merely determin- 
ing the composition of substances, and they very soon began 
eagerly to study their products of decomposition, and in this 
aa get a clue to the way in which nature had put them 
er 
The successful attack on this problem led to a much grander 
one suggesting itself. This was to utilize the insight analysis 
had given them into the constitution of substances, and to en- 
deavor to build them up without the assistance of life. The 
speaker showed that we thus arrive at the two great engines of 
chemical resedrch, analysis and synthesis. : 
He then proceeded to define and illustrate experimentally 
these terms, 
In organic chemistry the information supplied by the analysis 
of a substance often renders its synthesis easy. Water was de- 
fomposed by a battery, and its properties and quantitative re- 
lations shown i 
Soap-bubble, so prepared as to last a considerable time. It was 
Was then shown by applying a light to the bubble, when it burst 
With a loud seprk Phe quisialvee synthesis of water was 
€xperimentally shown by passing hydrogen over cupric oxyd in 
a0 apparatus which allowed of the collection of the water. It 
* From the Proceedings of the Royal Institution of Great Britain, May 8, 1868. 
