1.  That the effects of remedies upon the cerebro-spinal axis may be enhanced by the sequestration of the blood contained in one or more extremities, previous to the administration of the medicament.  This is only another way of saying that the quantity of a remedy required to produce a given physiological effect may be reduced by any expedient which suspends, or sequestrates, the blood in one or more extremities.  As has been previously said, however, care should be exercised to avoid dangerous exsanguination of the trunk, and consequently of the respiratory and cardiac centers contained in the medulla.  This may be done by compressing the central portion of both artery and vein; but I shall presently indicate a better way of accomplishing the same thing.

2.  The duration of the effect of a remedy upon the cerebro-spinal axis is in the inverse ratio of its volatility.  For this reason the anaesthetic effects of ether disappear shortly after removal of the inhaler, whereas solutions of antipyrin, phenacetin, morphine, and other salts possessing an affinity for nervous tissue exert much more permanent effects upon the cerebro-spinal system.

It is evident, therefore, that the administration of remedies designed to exert an influence upon the central nervous system in the form of gases must be far inferior to the exhibition of potent solutions hypodermically or by the mouth.

3.  The pharmaco-dynamic potency of stimulants, sedatives, analgesics, and probably of all remedies possessing a chemical affinity for nervous matter, is enhanced by exhibiting them (the remedies) in solution, or at least in soluble form while the subject remains in a condensed atmosphere.

And, as a corollary to this, it may be stated that this increase—­this enhancement of therapeutic effect—­is, within physiological limits, in the ratio of the atmospheric condensation.  By physiological limits we mean simply that there is a degree of atmospheric condensation beyond which we cannot go without jeopardizing the well-being of the subject.

(To be continued.)

* * * * *

EYESIGHT:  ITS CARE DURING INFANCY AND YOUTH.[1]

[Footnote 1:  A lecture delivered before the Franklin Institute, December 5, 1890.—­From the Journal of the Institute.]

By L. WEBSTER FOX, M.D.

Medical science, as taught in our medical colleges to-day, has two objects in view:  (1) the prevention of disease; (2) the amelioration of disease and its cure.  Some of our advanced thinkers are suggesting a new mode of practice, that is the prevention of disease by proper hygienic measures.  Chairs are being established and professors appointed to deliver lectures on hygiene.  Of what value is the application of therapeutics if the human economy is so lowered in its vital forces that dissolution is inevitable?  Is it not better to prevent disease than to try the cure after it has become established, or has honeycombed the constitution?