Hufeland, a well-known German professor, published towards the end of the eighteenth century, a work called "La Macrobiotique "; or, "the Art of Prolonging Human Life." This treatise had a great vogue in its day, and contained many interesting and just observations. Besides advocating cleanliness and moderation, Hufeland advised that "we should use vegetable rather than animal food, as animal food was more liable to putrefaction, whilst vegetable substances contained an acid principle that retarded our mortal enemy, putrefaction." Here the physician of a day long past anticipated one of the discoveries of modern science. In our time scientific men have not ceased to concern themselves with the prolongation of human life. Professor Pflüger, of Bonn, one of the most distinguished of living physiologists, has published an essay in which he gave the results of his inquiries into this subject. He first stated that investigations into the habits of those who had attained a great age did not give information sufficiently exact. Pflüger laid stress on the means of avoiding infectious maladies, and summed up as follows: "Finally, I can do no better than to associate myself with the advice given in all the treatises on the prolonging of life: avoid the things that are harmful and be moderate in all things." A year later, a well-known German physician, Dr. Ebstein§ published a very careful treatise on the same subject. He had been struck by the fact that among those who have reached a great age, there have been several who had led *"L'Art de Prolonger la Vie Humaine." French translation of German Second Edition. † Loc. cit. p. 296. Lausanne, 1809. Ueber die Kunst der Verlängerung des Menschlichen Lebens." Bonn, 1890. S Die Kunst das Menschliche Leben zu Verlängern." Wiesbaden, 1891. an exuberant life, full of excesses, notably in the consumption of alcohol. None the less, Ebstein advised either a complete avoidance of alcoholic liquor, or at the most an extreme temperance in the use of it. He prescribed in addition the simplification of the conduct of life and the avoiding of anything that is unwholesome. Study of such works, which are written in a scientific spirit, convinces me that a science of the prolongation of life could be built up. An exact investigation of the phenomena of old age would contribute to this object. At any rate, we cannot set aside as chimerical plans to make old age a natural process, and one easy to bear. I believe, moreover, that attempts to prolong life deserve to be encouraged, the more so as instances of longevity are already numerous. Quite a number of cases of centenarians who have preserved intellect and vigour until death have been recorded. It is unnecessary to relate the histories of these persons, of whom some attained such ages as 120, 140, and even 185 years (Saint Mungo of Glasgow). My friend, Professor Ray Lankester,* thinks that such unusually old persons are monstrosities comparable with those who have attained a gigantic stature. But centenarians are more numerous than giants, and while the latter exhibit marked signs of pathological weakness the former surprise us by their health and vigour. The longevity of the Israelites recorded in the Old Testament is well known. No doubt there is much exaggeration. in these naïve records. Was it an error of exaggeration to impute an age of 969 years to Methusaleh, or of 595 to Noah, or were these ages reckoned on a different basis? Henseler† suggested that in these cases each season was * The Advancement of Science," p. 237. London, 1890. † Quoted by Pflüger in "Ueber die Kunst der Verläng.," p. 14. counted as a year, so that the age of Methusaleh was really only 242 years, a length of life not so vastly greater than ages recorded in modern times. There is evidence to show that in somewhat later Biblical times ages were reckoned in our years. Thus in the Book of Numbers (i. 3, 20, 22) reference is made to those "From twenty years old and upward, all that are able to go forth to war in Israel." The limit of age given shows clearly that the years counted were our years. This interpretation is supported by many other passages in the Pentateuch, notably where annual harvest feasts are spoken of. We may therefore accept as probable the assignment of such ages as 100 or 120 years to several Biblical personages, such as Aaron, Moses, and Joshua. And the words put in the mouth of Jahveh may be accepted as important evidence: "And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years.' ""* The longevity of that remote period must have surpassed the age of the present time. From the circumstance that the greatest number of deaths occurs at the age of seventy years, Ebstein † has inferred that seventy years is the normal duration of life. Although there is no doubt but that the duration of human life has become longer in the nineteenth century, we must believe that it was still longer in Biblical times, a fact that is not particularly surprising. I have called attention to the important influence of syphilis in inducing premature and pathological old age, as that disease is a chief cause of arterial sclerosis and degeneration of the higher elements of the body. Syphilis has an influence still more serious because its effects are inherited. Now although the Bible refers to diseases of † Loc. cit. p. 12. * Genesis vi. 3. the genital organs and lays stress on circumcision, there is no direct evidence in it as to the existence of syphilis. Ebstein, in a treatise on the medicine of the Bible,* is confident that there is no reference to syphilis in that Book. Moreover, in the ancient world generally, syphilis was either unknown or existed only in an attenuated form. the author of the best modern treatise on the history of medicine, thinks that if syphilis did exist in the ancient world, it occurred in a localised form and did not become a general disease of the system as is the case among the moderns. Haeser,† Humanity would make a great stride towards longevity could it put an end to syphilis, which is the cause of onefifth of the cases of arterial sclerosis. The suppression of alcoholism, the second great factor in the production of senile degeneration of the arteries, will produce a still more marked extension of the term of life. Scientific study of old age and of the means of modifying its pathological character will make life longer and happier. Although modern knowledge is still imperfect, there is no reason to be pessimistic on the subject of old age. * "Die Medizin im alten Testament." Stuttgart, 1901. Lehrbuch d. Geschichte der Medecin," vol. III., p. 223. Jena CHAPTER XI INTRODUCTION TO THE SCIENTIFIC STUDY OF Theory of the immortality of lower organisms-Immortal- FROM what I have said in the last chapter, it is plain that, a century are much alike. they are over, three years or Such assertions, however, do not take into account the difference in the values we set on a thing at different ages. A man of the age of twenty-five years and one fifty years old reason differently, and are affected differently by the same surroundings. The outlook on life changes in the same |