other case in history of a man not a specialist in science accomplishing so much in original research as did Joseph Priestley, the chemist, physiologist, electrician; the mathematician, logician, and moralist; the theologian, mental philosopher, and political economist. He took all knowledge for his field; but how he found time for his numberless researches and multifarious writings, along with his every-day duties, must ever remain a mystery to ordinary mortals.

That this marvellously receptive, flexible mind should have refused acceptance to the clearly logical doctrines of the new chemistry seems equally inexplicable. But so it was. To the very last, after all his friends had capitulated, Priestley kept up the fight. From America, whither he had gone to live in 1794, he sent out the last defy to the enemy in 1800, in a brochure entitled "The Doctrine of Phlogiston Upheld," etc. In the mind of its author this was little less than a paan of victory; but all the world besides knew that it was the swan-song of the doctrine of phlogiston. Despite the defiance of this single warrior the battle was really lost and won, and, as the century closed, antiphlogistic" chemistry had practical possession of the field.

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VI.

Several causes conspired to make exploration all the fashion during the closing epoch of the eighteenth century. New aid to the navigator had been furnished by the perfected compass and quadrant and by the invention of the chronometer; medical science had banished scurvy, which hitherto had been a perpetual menace to the voyager; and, above all, the restless spirit of the age impelled the venturesome to seek novelty in fields altogether new. Some started for the pole, others tried for a northeast or north west passage to India, yet others sought the great fictitious antarctic continent told of by tradition. All these of course failed of their immediate purpose, but they added much to the world's store of knowledge and its fund of travellers' tales.

Among all these tales none was more remarkable than those which told of strange living creatures found in antipodal lands. And here, as did not happen in every field, the narratives were often substantiated by the exhibition of speci

mens that admitted no question. Many a company of explorers returned more or less laden with such trophies from the animal and vegetable kingdoms, to the mingled astonishment, delight, and bewilderment of the closet naturalists. The followers of Linnæus in the "golden age of natural history." a few decades before, had increased the number of known species of fishes to about 400, of birds to 1000, of insects to 3000, and of plants to 10,000. But now these sudden accessions from new territories doubled the figure for plants, tripled it for fish and birds, and brought the number of described insects above 20,000.

Naturally enough, this wealth of new material was sorely puzzling to the classifiers. The more discerning began to see that the artificial system of Linnæus, wonderful and useful as it had been, must be advanced upon before the new material could be satisfactorily disposed of. The way to a more natural system, based on less arbitrary signs, had been pointed out by Jussieu in botany, but the zoologists were not prepared to make headway toward such a system until they should gain a wider understanding of the organisms with which they had to deal through comprehensive studies of anatomy. Such studies of individual forms in their relations to the entire scale of organic beings were pursued in these last decades of the century, but though two or three most important generalizations were achieved (notably Kaspar Wolff's conception of the cell as the basis of organic life, and Goethe's all-important doctrine of metamorphosis of parts), yet, as a whole, the work of the anatomists of the period was germinative rather than fruit-bearing. Bichat's volumes, telling of the recognition of the fundamental tissues of the body, did not begin to appear till the last year of the century. The announcement by Cuvier of the doctrine of correlation of parts bears the same date, but in general the studies of this great naturalist, which in due time were to stamp him as the successor of Linnæus, were as yet only fairly begun.

In the field of physiology, on the other hand, two most important works were fairly consummated in this epoch-the long-standing problems of digestion and respiration were solved, almost coincidently. Two very distinguished physiologists share the main honors of discovery in re

gard to the function of digestion-the Abbe Spallanzani, of the University of Pavia, Italy, and John Hunter, of England. Working independently, these investigators showed at about the same time that digestion is primarily a chemical rather than a mechanical process. It is a curious commentary on the crude notions of mechanics of previous generations that it should have been necessary to prove by experiment that the thin, almost membranous stomach of a mammal has not the power to pulverize, by mere attrition, the foods that are taken into it. How ever, the proof was now for the first time forth-coming, and the question of the general character of the function of digestion was forever set at rest.

To clear up the mysteries of respiration was a task that fell to the lot of chemistry. The solution of the problem followed almost as a matter of course upon the advances of that science in the latter part of the century. Hitherto no one since Mayow, of the previous century, whose flash of insight had been strangely overlooked and forgotten, had even vague ly surmised the true function of the lungs. The great Boerhaave had supposed that respiration is chiefly important as an aid to the circulation of the blood; his great pupil, Haller, had believed to the day of his death in 1777 that the main purpose of the function is to form the voice. No genius could hope to fathom the mystery of the lungs so long as air was supposed to be a simple element, serving a mere mechanical purpose in the economy of the earth.

But the discovery of oxygen gave the clew, and very soon all the chemists were testing the air that came from the lungsDr. Priestley, as usual, being in the van. His initial experiments were made in 1777, and from the outset the problem was as good as solved. Other experimenters confirmed his results in all their essentials-notably Scheele and Lavoisier and Spallanzani and Davy. It was clearly established that there is chemical action in the contact of the air with the tissue of the lungs; that some of the oxygen of the air disappears, and that carbonic acid gas is added to the inspired air. It was shown, too, that the blood, having come in contact with the air, is changed from black to red in color. These essentials were not in dispute from the first. But as to just what chemical changes caused these re

sults was the subject of controversy. Whether, for example, oxygen is actually absorbed into the blood, or whether it merely unites with carbon given off from the blood, was long in dispute.

Each of the main disputants was biassed by his own particular views as to the moot points of chemistry. Lavoisier, for example, believed oxygen gas to be composed of a metal oxygen combined with the alleged element heat; Dr. Priestley thought it a compound of positive electricity and phlogiston; and Humphry Davy, when he entered the lists, a little later, supposed it to be a compound of oxygen and light. Such mistaken notions naturally complicated matters, and delayed a complete understanding of the chemical processes of respiration. It was some time, too, before the idea gained acceptance that the most important chemical changes do not occur in the lungs themselves, but in the ultimate tissues. Indeed, the matter was not clearly settled at the close of the century. Nevertheless, the problem of respiration had been solved in its essentials. Moreover, the vastly important fact had been established that a process essentially identical with respiration is necessary to the existence not only of all creatures supplied with lungs, but to fishes, insects, and even vegetables-in short, to every kind of living organism.

All advances in science have a bearing, near or remote, on the welfare of our race; but it remains to credit to the closing decade of the eighteenth century a discovery which, in its power of direct and immediate benefit to humanity, surpasses any other discovery of this or any previous epoch. Needless to say I refer to Jenner's discovery of the method of preventing smallpox by inoculation with the virus of cow - pox. It detracts nothing from the merit of this discovery to say that the preventive power of accidental inoculation had long been rumored among the peasantry of England. Such vague, unavailing half-knowledge is often the forerunner of fruitful discovery. To all intents and purposes Jenner's diseovery was original and unique. Neither, considered as a perfected method, was it in any sense an accident. It was triumph of experimental science; how great a triumph it is difficult now to understand, for we of to-day can only vaguely realize what a ruthless and ever-pres

a

ent scourge small- pox had been to all previous generations of men since history began. Despite all efforts to check it by medication and by direct inoculation, it swept now and then over the earth as an all-devastating pestilence, and year by year it claimed one-tenth of all the beings in Christendom by death as its average quota of victims. "From small-pox and love but few remain free," ran the old saw. A pitted face was almost as much a matter of course a hundred years ago as a smooth one is to-day.

Little wonder, then, that the world gave eager acceptance to Jenner's discovery. The first vaccination was made in 1796.

Of

Before the close of the century the method was practised everywhere in Christendom. No urging was needed to induce the majority to give it trial; passengers on a burning ship do not hold aloof from the life-boats. Rich and poor, high and low, sought succor in vaccination, and blessed the name of their deliverer. all the great names that were before the world in the closing days of the century, there was perhaps no other one at once so widely known and so uniformly rever enced as that of the English physician Edward Jenner. Surely there was no other one that should be recalled with greater gratitude by posterity.

· I.

MRS. LILLIAN INGLEHART AND MISS ROBERTA
LAWRENCE.

Mrs. Inglehart: "My dear! I will not hear another word. He is yours! The idea of making such a fuss about a little thing like the gift of a young man!"

Miss Lawrence: "It's only that I was afraid you might want him yourself, Mrs. Inglehart. It would make me unhappy if I thought you had deprived yourself of a cousin you might regret. They don't grow on every bush, I believe."

Mrs. Inglehart: "Such as Jim don't, I'll admit. But I hope I know the duties of a hostess, and the first of them is to get a young lady visitor engaged if possible. You've never seen Jim, have you?" Miss Lawrence : Never. What's he like?"

Mrs. Inglehart: "Are you very fond of tall men?"

Miss Lawrence : "Is he tall?" Mrs. Inglehart: "Not so very. I should say he had more breadth and thickness than length."

if they were doors. From the veranda, which extends around three sides of the house, broad steps descend to a driveway curving in front of it. Beyond the road green lawns, wept over by drooping white birches, slope to the red rocks that keep Mrs. Inglehart's place from the sea.

Mrs. Inglehart: Or not moment, exactly. He promised to be here by the half past four, but he probably won't come till the five-ten; it's only four, now."

Miss Lawrence: "Time enough to prink, then." She sinks back into her chair, provisionally. "Is Mr. Fairford punctilious about prinking?"

Mrs. Inglehart: "I see you would dread that.'

Miss Lawrence: "I don't know that I should. They have to have some fault." Mrs. Inglehart: And you think that

is a fault?"

Miss Lawrence: "I can't say that I do. Do you?"

Mrs. Inglehart, with an air of great candor: "To tell you the truth, I don't believe Jim cares about women's dress." Miss Lawrence: "Then he is the most

Mrs. Inglehart: "Do you?" She speaks with a certain intonation of misgiving, and then she has the effect of pulling herself together: "Do you like them brown-complexioned and dark-eyed?"

Miss Lawrence: "Is he brown-complexioned and dark-eyed?"

Mrs. Inglehart: "He's brown-complexioned and blue-eyed."

Miss Lawrence: "Oh, that sort of contradiction is adorable. The blue eyes always have such a funny look in the dark face. I shall like him, I know. When's he coming?"

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Mrs. Inglehart: Any moment, now." Miss Lawrence: "Oh!" She jumps to her feet. Mrs. Inglehart remains seated, but leans forward to look in through the door at the clock in the hall, from the veranda where, with a pretence of sewing, in her lap, she is talking with her guest. To the right of this hall the windows of a wide drawing-room open to the floor, and people come and go through them as

but he'll feel everything. to dress at his nerves."

I shall have

Mrs. Inglehart: "It's clear that you've made your observations, my dear." Miss Laurence: "By twenty-six, one has."

Mrs. Inglehart: "I should never have dreamt twenty-six."

Miss Lawrence: "I haven't dreamt it, myself. In my dreams I'm still sixteen. It's only in my waking moments that I'm twenty-six."

Mrs. Inglehart, thoughtfully: "You have courage.'

Miss Lawrence: "I have conviction. It's best to be honest unless the man prefers lies."

Mrs. Inglehart: "Don't they all?" Miss Lawrence: “ Nearly all. But if Mr. Fairford should happen to be the exception that doesn't, will you please tell him I owned to twenty-six, but you don't know how much older I really am?"

Mrs. Inglehart, with open admiration and covert alarm: "You're a strange girl."