left. It is hopeless to attempt learning from unprofessional bystanders or nurses what has gone on before, and he finds it necessary to certify that the person died of old age. Again, although the medical attendant is required to state in his certificate, not merely the immediate cause of death, but previous disorders, and the length of time they had existed, this is very imperfectly done, still more uncertainty attaching to the information he receives upon this point.

So far as the register points to external agencies as causes of fatal diseases, we may learn from it to avoid them, but it is evident that it throws no light on those numerous and oft unnoticed changes in the constitution of aged persons, which slowly and insidiously lead to overt disease, or to the debility and collapse recorded as old age.

My aim in these pages has been to specify and describe the very earliest indications of those changes, and to point out the measures they demand if we would prolong life to its normal

extent.

After middle life we should watch carefully, but without anxiety or fear, our own condition, and

take resolutely the proper steps to stay the first signs of mischief, neither neglecting the aid of medicine, nor employing it without good reason. There is a golden mean between scepticism and blind credulity.

If wisdom is ever to be attained, or common sense to rule the conduct, it is surely when life has extended beyond threescore years.

SUMMARY.

The views advanced in the preceding pages may be briefly summarized.

Ageing is a result of the operation of several concurring causes. Mere lapse of time will produce it. But ageing does not synchronize with age—that is, with the number of years a life has continued. In some persons it begins earlier and in others later.

Ageing consists in molecular changes proceeding in all the textures and organs of the body, involving a deterioration, degradation, or a species of decay. It may exist without suffering, or consciousness of the change. A person may say,

and truly, "I am quite well for an old man, or an old woman." The qualification implies that there is some degree of weakness, some departure of power formerly enjoyed, and the tendency is daily toward more and more debility.

We have shown it to be indisputable that certain appreciable conditions surrounding individuals change and retard the process of ageing, and thus prolong life. See ante, p. 8. These conditions, for the most part, seem to reach individuals fortuitously. If they are sought, studied, employed, why should not very many, instead of, as at present, very few, persons reap the benefit they confer, and attain to a good old age?

Nay; why should we not be able to augment the force of these conditions, and apply the resources of science to the same end, the arrest or retarding of ageing-and thus not merely increase the number of octogenarians, but extend human life to its utmost limit-100 years or beyond?

This should at least be the aim of our efforts. A close and careful consideration of the powers

L

and properties of substances known to act remedially on the body warrants the inference that the molecular action and changes of ageing are as amenable to their influence as any disease whatever. Experience alone, guided by so much physiology as will help us, must determine this.

There is another point of view in which we have somewhat fully regarded ageing, namely, it does not usually-or we should say, most commonly-proceed in all parts and organs alike, or within the same time. One part or organ ages (so to speak) before the others. Hence, elderly persons desirous of attaining longevity, and not unwilling to take some trouble in the matter, must learn for themselves the appearances, or symptoms of change in the more important, or vital organs at the very earliest moment, and take measures to remedy them; or they must incur the expense of employing a Physician to watch over them for the purpose.

They ought not to wait for suffering, or to postpone the search for relief. The health of every part is essential to the health of the whole; and the older we become the more certain is

disturbance in one vital organ to bring a fatal end to the whole, if neglected.

I do not hesitate to make this assertion, although Sir Henry Holland, in his essay on Old Age, expresses the contrary opinion. He says the sympathy between the several parts of the body and their influence on each other diminish with age. This does not accord with my observation. For instance, an indiscreet and heavy meal will sometimes produce a sudden collapse of power in the brain, before any of the food can have been digested. And again, intense headache will often disappear instantly on the use of an enema to empty the lower bowels.

These are results of sympathy; many such are observable in elderly people. I mention them to enforce the foregoing advice.

AN EXPERIMENT PROPOSED.

When Lady Mary Wortley Montague brought to England a report that in the East a practice prevailed of protecting persons from the worst evils of small-pox, by inoculation, public attention and interest was at once aroused. After