higher object of bringing the principles of the subject into relation with philosophical biology. The scientific significance of fermentation lies in the fact that it brings before us the action and effects of the lowest and most elemental forms of living organisms; it deals with the behavior and influence in numerous relations of elementary organisms reduced to a single cell; but these cells are the units of all organic life, a plant or an animal of a higher order being only the union under special laws of different kinds of cells, each of which acts in a certain determinable manner. While the higher organisms baffle analysis from the infinite complexity and diversity of their minute or histological elements, the key to their study is offered in these lower structures, for "the more simple an organism is, the fewer special kinds of cells it contains, the simpler are the chemical reactions which take place in it, and the more easily are they separated from each other and isolated by experiment;" and from this point of view the history of fermentation becomes nothing less than that of the chemical phenomena of life. The thorough study of ferments, therefore, becomes an indispensable scientific prerequisite to the knowledge of the higher organisms.
The investigation of the influence of different ferment-cells in initiating different lines of chemical change brings us into closer quarters with the relations of chemical and so-called vital forces. As the different radiant forces, thermal, luminous, and chemical, produce their profoundly diverse effects simply by variations of wave-length, so the different kind of cells are supposed to initiate different chemical changes by differences in the vibratory rhythm which starts them. In relation to this point our author remarks:
"The transformation of sugar into alcohol and carbon dioxide and the conversion of Hie same body into lactic acid are chemical phenomena which we cannot yet reproduce by the intervention of beat alone, nor by the additional agency of light or of electricity. The force capable of attacking, in a certain determinate direction, the complex edifice which we call sugar, an edifice composed of atoms of carbon, hydrogen, and oxygen, grouped according to a determinate law—this force, which is manifested only in the living cell of the ferment, is a force as material as all those which we are accustomed to utilize. Its principal peculiarity is, that it is only found I in the living organisms, to which it gives their peculiar character. We ought not to allow ourselves to be stopped by this rampart, over which no one has hitherto been able to pass; we ought not to say to the chemist, 'You shall go no farther, for beyond this is the domain of life, where you have no control.' The history of science shows us the weakness of these so-called impassable barriers. No one can any longer admit that vital force has power over matter, to change, counterbalance, or annul, the natural play of chemical affinities. That which we have agreed to call chemical affinity is not an absolute force; this affinity is modified in numberless ways, according as the circumstances vary by which bodies are surrounded. Thus, the apparent differences between the reactions of the laboratory and those of the organism ought to be sought for, more particularly among the special conditions, which the latter alone has been able hitherto to bring together. In other words, there is really no chemical vital force. If living cells produce reactions which seem peculiar to themselves, it is because they realize conditions of molecular mechanism which we have not hitherto succeeded in tracing, but which we shall, without doubt, be able to discover at some future time. Science can gain nothing by being limited in the possibility of the aims which she proposes to herself, or the end which she seeks."
Memoir of Sir Benjamin Thompson (Count Rumford), with Notices of his Daughter. By George E. Ellis. Published, in connection with an edition of Rumford's Complete Works, by the American Academy of Arts and Sciences. Boston. Pp. 680.
Rumford's Complete Works, vol. I., pp. 493. Vol. II., pp. 570. Vol. III., pp. 504. Vol. IV., pp. 842. Price of the set, including the "Life," $25.00. Boston: Estes & Lauriat.
We elsewhere publish a brief notice of the life of Count Rumford—so brief as hardly to give a just idea of the interest that attaches to the romantic and remarkable story of his career. But few biographies are richer in varied incident, or fuller of instruction, than this of Rumford; and its literary execution, by Mr. Ellis, is well worthy of the subject. The four volumes of his works comprise not only all the Count's essays, formerly published in English, but also valuable papers written by him in French and German which have been first translated for this edition. The collection has been supervised by the Rumford Committee of the American Academy of Sciences, who have grouped together in the several volumes, as far as was practicable, the papers on allied subjects: thus the sci-
