II. The calculus of chemical operations; being a method for the investigation by means of symbols, of the laws of the distribution of weight in chemical change. — Part II. On the analysis of chemical events

Abstract

“ The Observer is not he who merely sees the thing which is before his eyes, but he who sees what parts that thing is composed of .” —J. Stuart Mill. The first part of this Calculus was devoted to the construction of those rudimentary tools of analytical investigation termed Chemical Symbols. I have there given expression, by a system of arbitrary signs, to certain mental conceptions and combinations of conceptions which enter into exact chemical inquiries. This involves an analysis of those conceptions. But something more, too, is there effected. For the study of these questions necessitates the reconstruction (to a certain extent) of the fundamental ideas of the science and, especially, the reconsideration of a problem supposed to have been, long since, finally determined, namely, the constitution of the units of ponderable matter, of which I have given a new theoretical analysis. I shall not attempt to give any summary of these results, which, in my previous Memoir, have been discussed as briefly as is consistent with clearness. At the same time I should observe that the following pages can only be intelligible to those who have already made themselves acquainted with the principles of this Calculus, and to such alone they are addressed. There is, however, a point of fundamental importance which as yet has been only incidentally touched, namely, the origin of the hypothesis that the unit of hydrogen is an “undistributed weight,” which is the keystone of the system here adopted, and the reasons by which that hypothesis is justified, on which it is desirable, before proceeding further, to offer a somewhat fuller explanation. The following slight outline of the treatment of the subject pursued in this Calculus is given merely with the view of introducing these questions. For the effective consideration of the chemical properties of matter it is necessary to refer these properties to a common standard of comparison. Our first step, therefore, was the definition of the “Unit of ponderable matter” (I. Section I. (10)). In the selection of this unit we are guided by the same principles as those on which we select the unit of length, the unit of weight, the unit of heat, our choice being in all such cases determined by what is convenient for the special purpose in view’. Now the objects of our study are the chemical nature and transformations of gaseous matter. If, therefore, we wish to reason with impartiality, we must compare the properties of equal volumes of gases existing under the same conditions of temperature and pressure, for no reason can be assigned for comparing unequal volumes. All gases must be treated alike.