Volume Ii Part 21 (1/2)
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 gla.s.s 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 a.r.s.enals 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 leaders.h.i.+p in Pennsylvania, his several agencies abroad, his partic.i.p.ation 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 hara.s.s'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 Charite, 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 bal.u.s.trades 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 circ.u.mstance 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 Derbys.h.i.+re that the smoke from lead furnaces was pernicious to gra.s.s and other vegetables, and in America had often observed that streaks on s.h.i.+ngle roofs, made by white lead, washed from bal.u.s.ters 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 das.h.i.+ng 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 a.s.sist 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 Mult.i.tude of People, find their own Bodies heated; thence the quant.i.ty 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.
He did not shrink from any of the consequences of his reasoning about colds however extreme.
Be so kind as to tell me at your leisure [he wrote to Barbeu Dubourg], whether in France, you have a general Belief that moist Air, and cold Air, and damp s.h.i.+rts or Sheets, and wet Floors, and Beds that have not lately been used, and Clothes that have not been lately worn, and going out of a warm Room into the Air, and leaving off a long-worn Wastecoat, and wearing leaky Shoes, and sitting near an Open Window, or Door, or in a Coach with both Gla.s.ses down, are all or any of them capable of giving the Distemper we call _a Cold_, and you _a Rheum, or Catarrh_? Or are these merely _English_ ideas?
His views on the wholesomeness of fresh air were far in advance of the general intelligence of his time, and were expressed in spirited terms.
After stating in a letter to Jean Baptiste Le Roy that he had become convinced that the idea that perspiration is checked by cold was an error as well as the idea that rheum is occasioned by cold, he added: