REFLECTIONS ON PRA TER AND NA TURAL LA W. 345 
which our gem must be sought. A modified and more 
refined form of the ancient faith revived; and, for aught I 
know, a remnant of sanguine designers may at the present 
moment be engaged on the problem which like-minded men 
in former ages left unsolved. 
And why should a perpetual motion, even under modern 
conditions, be impossible? The answer to this question is 
the statement of that great generalization of modern 
science, which is known under the name of the Conser- 
vation of Energy. This principle asserts that no power 
can make its appearance in nature without an equivalent 
expenditure of some other power; that natural agents are 
so related to each other as to be mutually convertible, but 
that no new agency is created. Light runs into heat; 
heat into electricity; electricity into magnetism; magnet- 
ism into mechanical force; and mechanical force again into 
light and heat. The Proteus changes, but he is ever the 
same; and his changes in nature, supposing no miracle to 
supervene, are the expression, not of spontaneity, but of 
physical necessity. A perpetual motion, then, is deemed 
impossible, because it demands the creation of energy, 
whereas the principle of Conservation is no creation, but 
infinite conversion. 
It is an old remark that the law which molds a tear 
also rounds a planet. In the application of law in nature 
the terms great and small are unknown. Thus the prin- 
ciple referred to teaches us that the Italian wind, gliding 
over the crest of the Matterhorn, is as firmly ruled as the 
earth in its orbital revolution round the sun; and that the 
fall of its vapor into clouds is exactly as much a matter of 
necessity as the return of the seasons. The dispersion, 
therefore, of the slightest mist by the special volition of 
the Eternal, would be as much a miracle as the rolling of 
the Rhone over the Grimsel precipices, down the valley 
of Hasli to Meyringen and Brientz. 
It seems to me quite bevond the present power of science 
to demonstrate that the Tyrolese priest, or his colleague 
of the Rhone valley, asked for an " impossibility " in pray- 
ing for good weather; but Science can demonstrate the 
incompleteness of the knowledge of nature which limited 
their prayers to this narrow ground; and she may lessen the 
number of instances in which we "ask amiss," by showing 
that we sometimes pray for the performance of a miracle 
