THE CONSERVATION AND CORRELATION OF 
VITAL FORCE. 
BY J. T. ROTHROCK, M.D. 
gilts 
Ir is but lately that physicists have proven to the satisfaction 
of other men equally learned, that there does exist a series of 
compensations in the forces of nature ; and that heat, light, motion 
and other powers, more or less unknown, not only may be con- 
verted, the one into the other, but that their exact equivalents may 
be stated in infallible mathematics. This had been dimly fore- 
shadowed long ago, but its final proving belongs to our day. Vital 
force, however, from its very essence is more intractable, and over- 
rides mathematical restrictions, willing (so far as we can now see) 
to acknowledge similar relations of the most general character 
only. 
There is no denying that the most sublime mental endowments 
may in the same individual be associated with the most hopelessly 
ridiculous, and we are hence prepared to accept as true, or at least 
as not improbable, that the ‘ greatest, wisest ” of mankind could 
also be the “meanest.” Indeed, second thoughts may convince us 
that surpassing intelligence in one direction, implying unbroken 
devotion to a given line of study, almost of necessity, entails a 
corresponding ignorance in other lines of mental actiwity for which 
no leisure hours can be found. 
But whilst we are foiled in any attempt at estimating the exact 
amount of vital or purely mental force in excess in one direction, 
which it will require to compensate for a deficiency in some other, 
we may nevertheless, with some degree of certainty affirm that 
such relations do exist. : 
Geoffroy Saint-Hilaire not only recognizes the existence of thia 
principle of compensation, but has drawn largely upon it in his 
teratological studies. 
De Candolle, after granting the relation between excessive 
growth and atrophy, states that it is often exceedingly difficult to 
decide whether the former determines the latter, or the COn- 
verse.* 
* De Candolle, Theor. elem., ed. 1, § 73. 
