
Полная версия
Benjamin Franklin; Self-Revealed, Volume 2 (of 2)
In the latter part of Franklin's life, Noah Webster, the lexicographer, also formed a scheme for the reform of the alphabet, and Franklin had the pleasure of writing to him, "Our Ideas are so nearly similar, that I make no doubt of our easily agreeing on the Plan." Several years later, Webster, in his Dissertations on the English Language, stated that Franklin had compiled a dictionary, based upon his own reformatory system, and procured the types for printing it, but, finding himself too old to prosecute his design, had offered both manuscript and types to him. "Whether this project, so deeply interesting to this country," Webster said, "will ever be effected; or whether it will be defeated by insolence and prejudice, remains for my countrymen to determine."
Another thing upon which the ingenuity of Franklin was brought to bear, as the reader has already been told, was the Armonica. In his letter to Beccaria, extolling its merits, he describes it with a wealth of detail, not only thoroughly in keeping with his knack for mechanics, but showing that to music as to everything else, that won the favor of his intellect, he brought the ken of a man of science. The letter concludes with a dulcet compliment, which harmonizes well with its subject: "In honour of your musical language (the Italian), I have borrowed from it the name of this instrument, calling it the Armonica." In one of his papers, he drew up instructions for the proper use of the instrument which nothing but the most intimate familiarity with its operation could have rendered possible.
Admiration has often been expended upon the acuteness with which Franklin, in a letter to Lord Kames, accounted for the pleasure afforded by the old Scotch tunes, as compared with the pleasure afforded by the difficult music of his day, which, he said, was of the same nature as that awakened by the feats of tumblers and rope-dancers. The reason was this. The old Scotch melodies were composed by the minstrels of former days, to be played on the harp, accompanied by the voice. The harp was strung with wire (which gives a sound of long continuance) and had no contrivance like that in the modern harpsichord, by which the sound of the preceding note could be stopped, the moment a succeeding note began. To avoid actual discord, it was therefore necessary that the succeeding emphatic note should be a chord with the preceding, as their sounds must exist at the same time. Hence arose that beauty in those tones that had so long pleased, and would please forever, though men scarce knew why.
The most useful invention of Franklin was what came to be known as the Franklin stove. With modifications, it is still in use, and the essay written on it by Franklin, entitled An Account of the New-invented Pennsylvanian Fireplaces, is one of the best illustrations of the capacity of his scientific genius to adapt itself to the hardest and barest offices that human comfort and convenience could impose upon it with a nicety and accuracy of trained insight and touch worthy of the cleverest journeyman, a command of scientific principles to be expected only of a professional student, and a gift of clear, lively expression which reminds us of the remark of Stella that Dean Swift could write agreeably even about a broomstick. The principle upon which the Franklin stove was constructed was that of making the heat from its open fireplace, after first ascending to its top, descend in such a manner at its back, before passing off into the chimney, as to diffuse by radiation through the room, in which it stood, a large part of its warmth. The essay enumerates the different methods of heating rooms then in use: the great, open, smoky chimney-place, that the unremitting labor of one man could scarce keep supplied with fuel, and that gave out little more heat for human warmth than a fire outdoors; this chimney-place reduced to a smaller size with jambs, and free, to a great extent from the reproach of smokiness, yet, with its contraction setting up strong currents of whistling and howling air, which reminded Franklin of the Spanish proverb, the expensive and intricate French fireplaces with hollow backs, hearths and jambs of iron; the Holland stove, which shut off the sight of the fire, and could not conveniently be used for any purposes except those of warmth; the German stove which was subject to very much the same disadvantages as the Holland stove; and charcoal fires in pots which emitted disagreeable and dangerous fumes and were used chiefly in the shops of handicraftsmen. From the shortcomings of all these methods of heating rooms, the Franklin stove, its inventor contended, was exempt. It diffused heat equally throughout a whole room; if you sat in an apartment warmed by it, you were not scorched before, while you were frozen behind; nor were you exposed to the drafts from which so many women, particularly, got colds in the head, rheums and defluxions that fell upon their jaws and gums, and destroyed early many a fine set of teeth in the northern colonies, and from which so many persons of both sexes contracted coughs, catarrhs, toothaches, fevers, pleurisies and other diseases. It kept a sick room supplied with a fresh and yet properly tempered flow of pure air. It conserved heat. It economized fuel. With it, Franklin said, he could make his room twice as warm as it used to be with a quarter of the wood that he used to consume. If you burned candles near it, they did not flare and run off into tallow as in the case of ordinary fireplaces with their excessive drafts. It corrected most smoky chimneys. It prevented all kinds of chimneys from fouling, and if they fouled made them less likely to fire, and, if they fired, made the fire easier to repress. A flame could be speedily kindled in it with the help of the shutter or trap-bellows that went along with it. A fire could be readily extinguished in it, or could be so secured in it that not one spark could fly out of it to do any damage. A room once warmed remained warm all night. "With all these Conveniences," concludes Franklin, "you do not lose the pleasing Sight nor Use of the Fire, as in the Dutch Stoves, but may boil the Tea-Kettle, warm the Flat-Irons, heat Heaters, keep warm a Dish of Victuals by setting it on the Top, &c. &c."
"If the Wind blows on you thro' a Hole,Make your Will, and take Care of your Soul";Some years after the publication of this essay, Franklin devised an improvement in the open chimney-place which tended to abate drafts and check the escape of heat up the chimney by contracting the chimney opening, bringing its breast down to within three feet of the hearth, and placing an iron frame just under this breast, with grooves on each side of the frame, in which an iron plate could be slid backwards and forwards at pleasure, for the purpose of cutting off the mouth of the chimney entirely from the chimney itself, when there was no fire on the hearth, or of leaving a space of not more than two inches for the escape of smoke between the further edge of the plate and the back of the chimney-mouth. This improved chimney-place was described by Franklin in letters to Alexander Dick and James Bowdoin. The letter to Bowdoin seems to leave little to be said on the subject of chimneys. It indicates that Franklin had subjected them to a scrutiny hardly less close than that which he had fixed upon the Leyden Jar. In connection with the currents and reverse currents, set up in them in summer by the relations of inequality, which the air in them sustains, at different hours of the day and night, to the outside temperature, he suggests that joints of meat might keep for a week or more during the hottest weather in chimney-openings, if well wrapt three or four fold in wet linen cloths, sprinkled once a day with water to prevent evaporation. Butter and milk in vessels and bottles covered with wet cloths might, he thought, be preserved in the same way. And he even thought, too, that the movements of air in chimneys might, with the aid of smoke-jack vanes, be applied to some mechanical purposes, where a small but pretty constant power only was needed. To appreciate how patiently and exhaustively Franklin was in the habit of pursuing every course of observation or reflection opened up by his scientific propensities, the whole of this letter, which had much more to say on the subject of chimneys than we have mentioned, should be read.
At a later period of his life, Franklin describes to Turgot what he called his new stove. The novel feature of this consisted of an aerial syphon by which the smoke from the fireplace of the stove was first drawn upwards through the longer leg of the syphon, and then downwards through its shorter leg, and over burning coals, by which it was kindled into flame and consumed.
The ingenuity of Franklin was also exerted very successfully in the rectification of smoky chimneys. In his essay on the causes and cure of such chimneys, written on his last ocean voyage, he resolved the causes into no less than nine heads, and stated with his accustomed perspicuity and precision the remedy for each cause. In his time, the art of properly carrying off smoke through chimneys was but imperfectly understood by ordinary builders and mechanics, and it was of too humble a nature to tempt discussion by such men of science as were capable of clearly expounding the physical principles upon which it rested. It was not strange, therefore, that Franklin, who deemed nothing, that was useful, to be beneath the dignity of philosophy, should have acquired in his time the reputation of being a kind of "universal smoke doctor" and should have been occasionally consulted by friends of his, such as Lord Kames, about refractory chimneys. The only smoky chimney, that seems to have completely baffled his investigation, recalls in a way the philosopher, who thought that he had discovered a new planet, but afterwards found that what he saw was only a fly in the end of his telescope. After exhausting every scientific resource in an effort to ascertain why the chimney in the country-house of one of his English friends smoked, Franklin was obliged to own the impotence for once of his skill; but, subsequently, his friend, who made no pretensions to the character of a fumist, climbed to the top of the funnel of his chimney by a ladder, and, on peering down into it, found that it had been filled by nesting birds with twigs and straw, cemented with clay, and lined with feathers.
Nor was the attention given by Franklin to ventilation by any means confined to chimneys. Air vitiated by human respiration also came in for a share of it. Describing an experiment by which he demonstrated the manner in which air affected in this way is purified, Alexander Small said:
The Doctor confirmed this by the following experiment. He breathed gently through a tube into a deep glass mug, so as to impregnate all the air in the mug with this quality. He then put a lighted bougie into the mug; and upon touching the air therein the flame was instantly extinguished; by frequently repeating the operation, the bougie gradually preserved its light longer in the mug, so as in a short time to retain it to the bottom of it; the air having totally lost the bad quality it had contracted from the breath blown into it.
Franklin became deeply interested in the brilliant course of investigation pursued by Priestley with respect to gases, and several penetrating glances of his into the relations of carbonic acid gas to vegetation have come down to us. Observing on a visit to Priestley the luxuriance of some mint growing in noxious air, he suggested to Priestley that "the air is mended by taking something from it, and not by adding to it." He hoped, he said in a letter to Priestley, that the nutriment derived by vegetation from carbonic acid gas would give some check to the rage of destroying trees that grew near houses, which had accompanied recent improvements in gardening from an opinion of their being unwholesome.
Just as he was consulted about the best methods of protecting St. Paul's Cathedral and the arsenals at Purfleet from lightning, so he was also consulted by the British Government as to the best method for ventilating the House of Commons. "The personal atmosphere surrounding the members," he thought, "might be carried off by making outlets in perpendicular parts of the seats, through which the air might be drawn off by ventilators, so placed, as to accomplish this without admitting any by the same channels." The experiment might be tried upon some of our City Councilmen. Principles of ventilation, expounded by Franklin, were also utilized by the Messrs. Adam of the Adelphi, in the construction of the large room built by them for the meetings of the Society for the Encouragement of Arts. We also find him suggesting openings, close to the ceilings of rooms, and communicating with flues, constructed alongside of chimney flues, as effective means for ventilating rooms.
With all his primary and secondary gifts for scientific research, it is difficult to believe that, if Franklin had not been diverted from it by engrossing political cares, he would have added both to his special reputation as a student of electricity and to his general reputation as a man of science. As it was, his civic activity and popular leadership in Pennsylvania, his several agencies abroad, his participation in the American Revolution, his career as Minister to France, and his official duties, after his return, made such imperious demands upon his time that he had little or no leisure left for scientific pursuits. This picture of his situation which he presented in a letter to Ingenhousz, when he was in France, was more or less true of almost every part of his life after he became famous:
Besides being harass'd with too much Business, I am expos'd to numberless Visits, some of Kindness and Civility, many of mere idle Curiosity, from Strangers of America & of different Parts of Europe, as well as the Inhabitants of the Provinces who come to Paris. These devour my Hours, and break my Attention, and at Night I often find myself fatigu'd without having done anything. Celebrity may for a while flatter one's Vanity, but its Effects are troublesome. I have begun to write two or three Things, which I wish to finish before I die; but I sometimes doubt the possibility.
Some of the reflections of Franklin on scientific subjects, such as his early letters to Cadwallader Colden with regard to "perspirants and absorbents" are, to use his own expression in one of them, too plainly ultra crepidam to have any value. Of others, we might fairly say that his knowledge of the topics which he handled in them was hardly deep enough to deserve any praise more confident than that which he allowed himself when writing to Cadwallader Colden in 1751 of the Philadelphia Experiments. "So," he said to Colden in this letter, "we are got beyond the skill of Rabelais's devils of two years old, who, he humorously says, had only learnt to thunder and lighten a little round the head of a cabbage." All the same, even aside from his electrical experiments, Franklin acquired no little fame as a philosopher, made more than one fruitful suggestion to fellow-workers of his in the domain of science and contributed many useful observations to the general fund of scientific thought.
Apparently his views on medical topics were held in very considerable respect. In 1777, he was elected a member of the Royal Medical Society of Paris, and in 1787 an honorary member of the Medical Society of London. Many works on medical subjects were dedicated to him by their authors. He was one of the commission which exposed the imposture of Mesmer. There are few things that give us a better idea of the extraordinary celebrity enjoyed by him than the wide currency obtained by a spurious opinion of his, ascribing great merit to tobacco ashes as a remedy for dropsy. It won such an extensive circulation, and brought down on his head such a flood of questions from physicians and others, that he was compelled to deny flatly the truth of the story. One person, Lord Cadross, afterwards the Earl of Buchan, firmly believed that he would have perished at the hands of a professional physician, who wished to blister him, when he was afflicted with a fever, if Franklin had not dissented from the treatment. Franklin probably deserved no higher credit for his dissent on this occasion than that of sharing the opinion of Sir John Pringle, who was convinced that, out of every one hundred fevers, ninety-two cured themselves. So far as we can see, there is nothing in the works of Franklin to warrant the belief that he possessed any uncommon degree of medical knowledge, though he was full of curiosity with regard to medicine as with regard to every other branch of human learning. In one of his letters to Colden, written in his fortieth year, he expressed the hope that future experiment would confirm the idea that the yaws could be cured by tar-water. In a later letter to Colden, he expressed his pleasure at hearing more instances of the success of the poke-weed "in the Cure of that horrible Evil to the human Body, a Cancer." At his suggestion, a young physician, with the aid of Sanctorius' balance, tested alternately each hour, for eight hours, the amount of the perspiration from his body, when naked, and when warmly clad, and found that it was almost as great during the hours when he was naked. By his investigations into the malady known in his time popularly as "the dry bellyache," and learnedly as the "colica Pictonum," he conferred a real benefit upon medical science. His views upon the subject received the honor of being incorporated with due acknowledgments into Dr. John Hunter's essay on the Dry Bellyache of the Tropics. Summarily speaking they were that the complaint was a form of lead poisoning.
I have long been of opinion [he wrote to Dr. Cadwallader Evans in 1768] that that distemper proceeds always from a metallic cause only; observing that it affects, among tradesmen, those that use lead, however different their trades, – as glaziers, letter-founders, plumbers, potters, white-lead makers, and painters;… although the worms of stills ought to be of pure tin, they are often made of pewter, which has a great mixture in it of lead.
The year before this letter was written, Franklin had found on reading a pamphlet, containing the names and vocations of the persons, who had been cured of the colic at Charité, a Parisian hospital, that all of them had followed trades, which handle lead in some form or other. On going over the vocations, he was at first puzzled to understand why there should be any stonecutters or soldiers among the sufferers, but his perplexity was cleared up by a physician at the hospital, who informed him that stonecutters frequently used melted lead for fixing the ends of iron balustrades in stone, and that the soldiers had been employed as laborers by painters, when grinding colors. These facts were long afterwards communicated by Franklin to Benjamin Vaughan in a letter, in which he cited other incidents, interesting partly because they corroborated his theory, and partly because they are additional proofs of his vigilance and patience in collecting facts, before advancing an hypothesis, as well as of a memory, which retained every instructive circumstance imparted to it by eye or ear as imperishably as hardening cement retains the impression of a dog's foot. When he was a boy at Boston, Franklin said, it was discovered that New England rum, which had produced the dry bellyache and paralyzed the limbs in North Carolina, had been made by distilleries with leaden still-heads and worms. Later, when he was in London, he had been warned by an old workman at Palmer's printing-house, as well as by an obscure pain in his own hands, that it was a dangerous practice to handle a heated case of types. About the same time, a letter-founder in the same close at Palmer's, in a conversation with him, ascribed the existence of the ailment among his workmen to the fact that some of them were slovenly enough to go to their meals with unwashed hands that had come into contact with molten lead. He had also observed in Derbyshire that the smoke from lead furnaces was pernicious to grass and other vegetables, and in America had often observed that streaks on shingle roofs, made by white lead, washed from balusters or dormer window frames, were always entirely free from moss. He had also been told of a case where this colic had afflicted a whole family, and was supposed to be due to the corrosive effect of the acid in leaves, shed upon the roof, from which the family derived the supply of rain water, upon which it relied for drink.
More important still than the insight that Franklin obtained into the Painter's Colic was the insight which he obtained into the salutary effect of the custom which is now almost universal, except in the homes of the ignorant and squalid, of sleeping at night in rooms with the windows up. This custom, as well as the outdoor regimen, which has proved of such signal value in the treatment of tuberculosis, originated in hygienic conceptions identical with those steadfastly inculcated by him. His opinions with regard to colds and the benefits of pure air were expressed at many different times, and in many different forms, but nowhere so conveniently for the purposes of quotation as in a letter which he wrote to Dr. Benjamin Rush in 1773.
I hope [he said in this letter] that after having discovered the benefit of fresh and cool air applied to the sick, people will begin to suspect that possibly it may do no harm to the well. I have not seen Dr. Cullen's book, but am glad to hear that he speaks of catarrhs or colds by contagion. I have long been satisfied from observation, that besides the general colds now termed influenzas (which may possibly spread by contagion, as well as by a particular quality of the air), people often catch cold from one another when shut up together in close rooms, coaches, &c., and when sitting near and conversing so as to breathe in each other's transpiration; the disorder being in a certain state. I think, too, that it is the frouzy, corrupt air from animal substances, and the perspired matter from our bodies, which being long confined in beds not lately used, and clothes not lately worn, and books long shut up in close rooms, obtains that kind of putridity, which occasions the colds observed upon sleeping in, wearing, and turning over such bedclothes, or books, and not their coldness or dampness. From these causes, but more from too full living, with too little exercise, proceed in my opinion most of the disorders, which for about one hundred and fifty years past the English have called colds.
As to Dr. Cullen's cold or catarrh a frigore, I question whether such an one ever existed. Travelling in our severe winters, I have suffered cold sometimes to an extremity only short of freezing, but this did not make me catch cold. And, for moisture, I have been in the river every evening two or three hours for a fortnight together, when one could suppose I might imbibe enough of it to take cold if humidity could give it; but no such effect ever followed. Boys never get cold by swimming. Nor are people at sea, or who live at Bermudas, or St. Helena, small islands, where the air must be ever moist from the dashing and breaking of waves against their rocks on all sides, more subject to colds than those who inhabit part of a continent where the air is driest. Dampness may indeed assist in producing putridity and those miasmata which infect us with the disorder we call a cold; but of itself can never by a little addition of moisture hurt a body filled with watery fluids from head to foot.
Franklin's belief that colds and overeating often went hand in hand also found expression in one of his letters to Polly Stevenson. When sending her an account of some seamen, who had experienced considerable relief from thirst by wearing clothes kept constantly wet with salt water, he said, "I need not point out to you an Observation in favour of our Doctrine, that you will make on reading this Paper, that, having little to eat, these poor People in wet Clothes Day and Night caught no cold." In every, or in practically every, case, he seems to have referred colds to what he rather vaguely calls a siziness and thickness of the blood, resulting from checked perspiration, produced by different agencies, including a gross diet.
Thus [he says in his Notes and Hints for Writing a Paper Concerning what is called Catching Cold], People in Rooms heated by a Multitude of People, find their own Bodies heated; thence the quantity of perspirable Matter is increased that should be discharged, but the Air, not being changed, grows so full of the same Matter, that it will receive no more. So the Body must retain it. The Consequence is, the next Day, perhaps sooner, a slight putrid Fever comes on, with all the Marks of what we call a Cold, and the Disorder is suppos'd to be got by coming out of a warm Room, whereas it was really taken while in that Room.