[10] The force, however, of this last consideration has been much weakened by the progress of discovery since M. Comte left off studying chemistry; it being now probable that most if not all substances, even elementary, are susceptible of allotropic forms; as in the case of oxygen and ozone, the two forms of phosphorus, &c.

[11] Thus; by considering prussic acid as a compound of hydrogen and cyanogen rather than of hydrogen and the elements of cyanogen (carbon and nitrogen), it is assimilated to a whole class of acid compounds between hydrogen and other substances, and a reason is thus found for its agreeing in their acid properties.

[12] According to Sir William Hamilton, as many as six; but numerical precision in such matters is out of the question, and it is probable that different minds have the power in different degrees.

[13] Or, as afterwards corrected by him, the appetites and emotions, the active capacities, and the intellectual faculties; “le coeur,” “le caractere,” and “l’esprit.”

[14] M. Littre, who, though a warm admirer, and accepting the position of a disciple of M. Comte, is singularly free from his errors, makes the equally ingenious and just remark, that Political Economy corresponds in social science to the theory of the nutritive functions in biology, which M. Comte, with all good physiologists, thinks it not only permissible but a great and fundamental improvement to treat, in the first place, separately, as the necessary basis of the higher branches of the science:  although the nutritive functions can no more be withdrawn in fact from the influence of the animal and human attributes, than the economical phaenomena of society from that of the political and moral.

[15] Indeed his claim to be the creator of Sociology does not extend to this branch of the science; on the contrary, he, in a subsequent work, expressly declares that the real founder of it was Aristotle, by whom the theory of the conditions of social existence was carried as far towards perfection as was possible in the absence of any theory of Progress.  Without going quite this length, we think it hardly possible to appreciate too highly the merit of those early efforts, beyond which little progress had been made, until a very recent period, either in ethical or in political science.

[16] It is due to them both to say, that he continued to express, in letters which have been published, a high opinion of her, both morally and intellectually; and her persistent and strong concern for his interests and his fame is attested both by M. Littre and by his own correspondence.

[17] “Of the Classification of the Sciences,” pp. 37, 38.