﻿ATOMIC HEAT TO CRYSTALLINE FORM. 133 



and dignity of its influence upon the self-inert bases with which it is combined, we 

 open a channel for the hopeful investigation of cause and effect. Changes in the 

 properties of things must be preceded by compositional and structural changes, either 

 of their ponderable or imponderable element, or of both, just as in the animate world 

 organic derangement is the invariable antecedent to functional disturbance. If caloric 

 be merely a property or quality of matter, it cannot possess that self-active and 

 causative power which a careful analysis of its history warrants us in assigning to it. 

 If it be a substantive entity, we can readily understand the remarkable constancy and 

 mathematical precision of its effects ; and we can understand, furthermore, how its 

 presence or absence in certain quantities can produce those structural or molecular 

 alterations which manifest themselves externally in variations of form, specific gravity, 

 color, solubility, &c. The estimation of the absolute amount of heat combined with 

 bodies in their different states of aggregation, is one of the most difficult problems in 

 physical science ; — and one of the most important, since upon its solution depends the 

 explanation of many unexplained and apparently inexplicable phenomena. However, 

 if we bring together the few reliable observations that have been made in this channel, 

 (especially those concerning the relation between the calorific condition and refractive 

 power of substances,) and the numerous collateral facts which are scattered throughout 

 the literature of physics, we will have material sufficient to begin already the work of 

 cautious and satisfactory generalization. 



The following conclusions, as being more or less probable, seem to flow naturally 

 from the foregoing facts and arguments : — 



1. That no invariable connection exists between the form and ponderable atomic 

 constitution of a body. 



2. That form is immediately dependent upon peculiar axial proportions, which are 

 themselves the results of a certain molecular arrangement. 



3. That the arrangement and disarrangement of atoms implies a motor agent • 

 while the definite and constant relation between changes in aggregation and variations 

 in form, implies the materiality of this agent and its continued presence, whether in 

 the same or varying quantities. 



4. That this agent has periods of action and periods of rest. 



5. That caloric is a positive material entity — an essential element in all bodies 

 always present in different proportions. 



6. That caloric is self-repellant and endowed with great physical power. 



7. That crystalline form is the visible representative of atomic volume. 



8. That isomorphous bodies have sensibly the same atomic heat and the same 

 atomic volume. 



9. That in elementary and compound isomorphous groups, the numbers indicating 

 atomic heat and volume are simply related. 



