ON CATALYSIS. 
221 
not being in combination, was, by means of alkalies, repro- 
duced in its primitive quantity, and the liquid contained sugar, 
rather greater in quantity than the amidon employed. The 
cause of this change was thus quite as problematical as those 
of the secretions in organized bodies. 
After relating many observations of MM. Thenard and 
Gay Lussac, concerning substances determining chemical re- 
actions without being themselves changed, the author adds: 
"The change of amidon into sugar, by means of sulphuric 
acid, had not yet been classed with the preceding facts. In 
the mean while, the discovery of diatase, (announced in the 
year 1833,) a substance acting upon amidon in an analogous 
manner, only with more energy, drew attention to this ana- 
logy, which was definitely proven by the ingenious researches 
of Mitscherlich upon the formation of ether. The investiga- 
tions of Mitscherlich proved, likewise, that sulphuric acid, 
suitably diluted, and at a temperature such that the cold pro- 
duced by the addition of the alcohol compensated for the 
elevation of temperature in the mixture, decomposes alcohol 
into ether and water, and that, when the temperature surpasses 
that of boiling water, both separate by the distillation of the 
mass, and present, when the condensation is complete, a 
mixture of the same weight as that of the alcohol employed. 
The mode of operating in this experiment, as well as the fact 
of the. distillation of the ether, together with the water, was 
known before Mitscherlich, but it is to him that the merit is 
due, of perceiving the consequences. In fact, he demonstrated 
that, at this temperature, the sulphuric acid acts upon the 
alcohol in virtue of the same force which determines the 
action of the alkalies upon oxygenated water, and since the 
water, in separating itself entirely from the mixture, did not 
obey an affinity for the acid, he concluded that the action of 
sulphuric acid and of diatase upon amidon, from which sugar 
results, should likewise be of the same nature. 
Truly, such a force, capable of effecting chemical reactions 
in inorganic nature as well as in organized bodies, although 
as yet too little known to be well explained, should play a 
vol. in. — NO. iv. 29 
