of the relative proportions between these two processes; and the state of depression, or more properly paresis, resembles all matters of currency in depending upon the degree of solvency of the bank and the amount of assistance which may be given to it from without.

This brings us to another subject. The moral emotions are allowed to have a more powerful effect on our frame than any amount of intellectual exertion and excitement, the link between the two, produces more speedy exhaustion than physical or mental labour. Although the heart is the reputed seat of the affections, their real centre would be more correctly described as that portion of the nervous system which regulates the action of the heart; and as we cannot properly treat the physical conditions of blood-vessels and other structures without taking into account the nerve-power which regulates them, neither, in a higher sense, can we treat lesions of the nervous system without recognising the moral power which sustains or depresses it, and thus it not infrequently happens that, in order to relieve the disorders of the body, we must first minister to the mind diseased and pluck from the memory the rooted sorrow.

It is present to the mind of all, that the blood

vessels are placed under the control of two classes of nerves: one derived from the sympathetic, producing contraction of calibre; the other, connected with the cerebro-spinal, presiding over dilatation.

The glands are similarly supplied with two classes of nerves

1. The sympathetic, producing contraction of the secreting vessels.

2. The cerebro-spinal, ramifying in the immediate vicinity, influencing dilatation.

The experiments of M. Claude Bernard have shown that the following phenomena occur after division of the sympathetic :

1. Dilatation of vessels, with increased rapidity of circulation;

2. Impeded interchange between blood-vessels, arterial blood retaining much of its venous character; 3. Increase of temperature, and

4. Of absorption;

5. Increase of muscular irritability, of temperature of surface, of vascularity, and general sensibility of cerebro-spinal nerves, constituting hyperæsthesia; 6. Function of secretions are deranged;

7. As long as animals are kept in good condition they do not suffer from division of sympathetic; all

excito-motory functions, even those of reproduction, are performed, but if condition be reduced the health fails proportionately.

Dr. Stevenson, of Edinburgh, has compared the symptoms of rickets with the phenomena resulting from division of the sympathetic—

1. Increased vascular action, visible pulsation of carotid ;

2. Increased temperature of body, and local sweating, especially during sleep;

3. Increased nervous susceptibility and desire to be cool, indicated by kicking off the bed-clothes.

In Mollitus Ossium we find a similar class of symptom, only associated with the wasting of bonestructure, instead of, as in rickets, interfering with its development; and although subjects of this disease are mostly weakly persons, who had experienced more or less privations, almost all had been subject either to excessive expenditure of strength or to anxiety of mind.

Moreover, both classes of case are subject to excess of phosphates in the urine, and phosphorus, we know, enters largely into the composition both of nerve and bone; and as not only the contraction and dilatation of vessels, but the secretions of the glands, and the

absorption, the deposit and repair of tissues are regulated by nerve influence, the impairment of power of the nervous system by exhaustion from excessive use or effort is still further increased and promoted by the depression arising from mental emotion; and we cannot but recognise the fact that this cause leads to alteration of secretion, to impairment of structure and waste of tissue as certainly and directly as actual division by the knife, in fact, to a state of paresis more or less complete, either by simple leakage, or impairment of vaso-motory power in its most minute ramifications; also, that different constitutions and states of health are variously affected thereby,-the phosphatic diathesis being perhaps that which is most predisposed to it; the effect is similar in other temperaments, though it may not be equally capable of demonstration.

The excessive loss of phosphates is found to be coincident with acute mania, with paralysis from excessive waste, and that caused by lesion of the spinal cord. Again, the decomposition of urea leads to the evolution of ammonia and deposits of the earthy phosphates; in another class of case the vice of system is associated with profuse acid perspirations. In all forms arising from these various causes, the

main object of treatment is obviously the restoration to the system of the lost material, and the internal administration of phosphoric acid has been recommended as the readiest means of accomplishing this; but how far does this plan resemble the task of endeavouring to fill the vessel of the Danaides? how far is it treating the symptoms, instead of remedying the cause? If we revert to the physiology of digestion, we find that the gastric juice secreted by the gastric glands consists principally of hydrochloric and other acids, and pepsine; and it is worthy of remark that several cases of paralysis, taking most frequently the form of paraplegia, have come under my notice, the main exciting cause of which was anxiety of mind. In these, treatment by direct tonics, steel, quinine, and even strychnine failed to produce a good effect, but steady and gradual improvement followed the administration of nitro-hydrochloric acid, persevered in for some length of time. The same treatment is sometimes successful in non-uniting bone after fracture. This gives rise to the hypothesis that anxiety of mind and other sources of mental depression cause paresis of the sympathetic in a greater or less degree: that this becomes associated with the spinal paresis in the production of paralysis