truth. And in connection with this remark allusion may here be made to one or two of the many recent researches in Physical Science. In a work just published,* Professor P. G. Tait speaks of "the Law of the Dissipation of Energy, discovered by Sir W. Thomson," and adds that it has already led to an important discovery which refutes the Uniformitarian theories of geologists:

"It enables us distinctly to say, that the present order of things has not been evolved through infinite past time by the agency of laws now at work, but must have had a distinct beginning a state beyond which we are totally unable to penetrate, a state which must have been produced by other than the now (visibly) acting causes."

And, arguing from our present knowledge of radiation, against the claims of

"Lyell and others, especially of Darwin, who tell us that even for a comparatively brief portion of recent geological history three hundred millions of years will not suffice,"

Professor Tait quotes Sir W. Thompson's three lines of argument, and urges

"Ten million years as the utmost we can give to geologists for their speculations as to the history even of the lowest orders of fossils [and] for all the changes that have taken place on the earth's surface since vegetable life of the lowest known form was capable of existing there."

Of course, it remains to be seen how far future researches may induce others to modify the above statements. An example of the change in our conceptions of Nature resulting from recent investigations, is afforded by the fact that whilst the use of improved telescopes was considered to have resolved some of the nebulæ into multitudes of stars, spectrum analysis now shows them to be, wholly or in part, masses of glowing or incandescent gas. These remarks can scarcely be concluded without a reference to the researches into what Professor

* Recent Researches in Physical Science, 2nd Edition, 1876.

;

Lionel Beale, F.R.S., has called "the Mystery of Life" upon which Professor G. G. Stokes, F.R.S., no mean authority among scientific men (see Nature, No. 298), recently remarked (in his Address as President of the British Association in 1872):

"What this something, which we call Life, may be, is a profound mystery. We know not how many links in the chain of secondary causation may yet remain behind; we know not how few. It would be presumptuous indeed to assume in any case that we had already reached the last link, and to charge with irreverence a fellow-worker who attempted to push his investigations yet one step further back. On the other hand, if a thick darkness enshrouds all beyond, we have no right to assume it to be impossible that we should have reached even the last link of the chain, a stage where further progress is unattainable; and we can only refer the highest law at which we stopped to the fiat of an Almighty Power. To assume the contrary as a matter of necessity, is practically to remove the First Cause of All to an infinite distance from us. The boundary, however, between what is clearly known and what is veiled in impenetrable darkness is not ordinarily thus sharply defined. Between the two there lies a misty region, in which loom the ill-discerned forms of links of the chain which are yet beyond us but the general principle is not affected thereby. Let us fearlessly trace the dependence of link on link as far as it may be given us to trace it, but let us take heed that in thus studying second causes we forget not the First Cause, nor shut our eyes to the wonderful proofs of design which, in the study of organized beings especially, meet us at every turn."

F. PETRIE,

DECEMBER 30, 1876.

Hon. Sec. and Editor.

truth. And in connection with this remark allusion may here be made to one or two of the many recent researches in Physical Science. In a work just published,* Professor P. G. Tait speaks of "the Law of the Dissipation of Energy, discovered by Sir W. Thomson," and adds that it has already led to an important discovery which refutes the Uniformitarian theories of geologists:

"It enables us distinctly to say, that the present order of things has not been evolved through infinite past time by the agency of laws now at work, but must have had a distinct beginning a state beyond which we are totally unable to penetrate, a state which must have been produced by other than the now (visibly) acting causes."

And, arguing from our present knowledge of radiation, against the claims of

"Lyell and others, especially of Darwin, who tell us that even for a comparatively brief portion of recent geological history three hundred millions of years will not suffice,"

Professor Tait quotes Sir W. Thompson's three lines of argument, and urges

"Ten million years as the utmost we can give to geologists for their speculations as to the history even of the lowest orders of fossils [and] for all the changes that have taken place on the earth's surface since vegetable life of the lowest known form was capable of existing there."

Of course, it remains to be seen how far future researches may induce others to modify the above statements. An example of the change in our conceptions of Nature resulting from recent investigations, is afforded by the fact that whilst the use of improved telescopes was considered to have resolved some of the nebulæ into multitudes of stars, spectrum analysis now shows them to be, wholly or in part, masses of glowing or incandescent gas. These remarks can scarcely be concluded without a reference to the researches into what Professor

* Recent Researches in Physical Science. 2nd Edition, 1876.

Lionel Beale, F.R.S., has called "the Mystery of Life"; upon which Professor G. G. Stokes, F.R.S., no mean authority among scientific men (see Nature, No. 298), recently remarked (in his Address as President of the British Association in 1872):

"What this something, which we call Life, may be, is a profound mystery. We know not how many links in the chain of secondary causation may yet remain behind; we know not how few. It would be presumptuous indeed to assume in any case that we had already reached the last link, and to charge with irreverence a fellow-worker who attempted to push his investigations yet one step further back. On the other hand, if a thick darkness enshrouds all beyond, we have no right to assume it to be impossible that we should have reached even the last link of the chain, a stage where further progress is unattainable; and we can only refer the highest law at which we stopped to the fiat of an Almighty Power. To assume the contrary as a matter of necessity, is practically to remove the First Cause of All to an infinite distance from us. The boundary, however, between what is clearly known and what is veiled in impenetrable darkness is not ordinarily thus sharply defined. Between the two there lies a misty region, in which loom the ill-discerned forms of links of the chain which are yet beyond us but the general principle is not affected thereby. Let us fearlessly trace the dependence of link on link as far as it may be given us to trace it, but let us take heed that in thus studying second causes we forget not the First Cause, nor shut our eyes to the wonderful proofs of design which, in the study of organized beings especially, meet us at every turn."

F. PETRIE,

DECEMBER 30, 1876.

Hon. Sec. and Editor.