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Dalton's

Theory

The Atomic

the Ultimate Particles of Gaseous and Dalton made out a clear view of what other Bodies,” which he put at the end of atoms are. All atoms of the same kind his essay read October 21, 1803, and pub- must necessarily be conceived, he said, to lished in November, 1805.

be alike in shape, weight and every other Dalton wrote at this time: “An in particular, while in different substances quiry into the relative weights of the ul the atoms must be different in weight and timate particles of bodies is a subject, as other characteristics. far as I know, entirely new; I have lately been prosecuting this inquiry with re

The especially important markable success. The principle cannot

and altogether new part be entered upon in this paper; but I shall of Dalton's theory was that which dealt just subjoin the results as far as they ap with the relative weights of the ultimate pear to be ascertained by my experi particles of bodies. Here he was making ments."

an investigation which, as we have seen

that he said, was entirely new, and the Dalton was not the first to success with which he prosecuted it made Theory propose the theory which possible the science of chemistry as it now makes all matter consist of atoms. The exists. Dalton fonnd, for example, that Greek and Roman philosophers, wise every atom of the same element has the men of the East in Egypt and India, and same unalterable weight and that the such eminent moderns as Sir Isaac New various atoms differ in weight; oxygen, ton and Leibnitz had advocated the the- for example, being several times heavier ory in some form. Democritus (E. B., than hydrogen. A remarkable feature Vol. VII. 59) had advanced a form of of the doctrine of atoms, as Dalton conthe theory, not only the earliest, but the ceived it, appears in what he says of an most remarkable in the history of sci- atom as a hard particle surrounded by an ence. Among the moderns, Newton had atmosphere of heat. This would seem to insisted on the existence in all bodies of mean a space which the hard particle ocunbreakable, unwearable, impenetrable cupied in vibrating. Intensity of vibraparticles, each kind of which remains tion in various degrees is thus understood always the same in size, weight, figure to belong to all atoms. and force, so that however compounded, The discovery of Dalton was brought the nature and texture of the compounds before the world, not by himself, but by are always the same.

Dr. Thomas Thomson, a professor of

chemistry at Glasgow. Dr. Thomson beAtoms

The distinction of Dalton came an ardent disciple of Dalton's doc

is that he applied to the trine from conversation with him in Manexistence of atoms a theory which ren- chester. He introduced the new doctrine dered it possible to explain, in accord into his lectures and brought it out in his ance with clear and distinct principles, text-book, published in 1807. Dalton all those changes, an account of which himself published his researches in the constitutes the science of chemistry. “New System of Chemical Philosophy," Newton's theory of atoms was one of the first edttion of which was dated May, Dalton's favorite studies, and he very 1808. early applied it to the explanation of the Sir Henry Roscoe remarks, with the diffusion of the particles of water, or highest authority known to modern sciaqueous vapor, in the atmosphere, and ence, that without the Daltonian atomic also to the mingling of the other con- theory, modern chemistry would be a stituents of the air. He clearly distin- chaos, while with it, order reigns suguished the particles of aqueous vapor, of preme, and every apparent and recondite oxygen, and of nitrogen, as each having discovery only marks out more distinctly its own individuality, not only of form, the value and importance of Dalton's but of action, and this brought him to work. Dalton's methods of experimenthe threshold of his great theory that all tation were indeed rough. He is, in fact, bodies, and not familiar gases only, are the monumental instance of thinking in formed of characteristic atoms.

science, not slavishly bound to experiAmong the papers which he left full ment. He was not, as Sir Henry Roscoe evidence is found that it was in the study says must be admitted, at all great in exof the constituents of the atmosphere that act experimental chemistry. He seems even to have lacked something in either make any reopening of important queshis mind or his hands, without which he tions extremely difficult, if not quite imcould not be a great experimenter. His possible. Darwinism, for example, has apparatus and appliances were often of become a creed, many of the adherents of the rudest kind.

which are as bigoted, as stone-blind to But, as Sir Henry Roscoe remarks, looking any farther or seeing anything Dalton's "results stand out the greatest else, as any religious dogmatist ever was. landmarks in the science of chemistry. Huxley earnestly warned against this His great achievement was that he was long since. He understood the danger the first to introduce the idea of quantity of confidence so extreme as to shut out into chemistry. The atomic theory was all new light. Dalton did not. He indeed old, but no one before Dalton was wanting somewhat, also, in the used the theory of atoms to explain chem- broader sympathies commonly created ical phenomena. To him is due the gloryby a liberal education. He took no of placing the science on a firm basis, by part in social, much less in political, matshowing that the weights of the atoms of ters. He was, on the whole, a silent the different elements are not identical, man, and could sometimes be rough and but different, and that a combination even rude in his manners. His converamongst these elements takes place if sational powers were seen at their best more than one compound be formed of when surrounded by a few congenial the same elements, in simple arithmetical spirits enjoying a pipe of tobacco. He proportion.”

thought it a failure in the character of In Dalton's day the greatest figure in Sir Humphrey Davy that he didnot smoke. the world of science was Sir Humphrey Davy. Davy hesitated to accept Dalton's

The

He always dressed in the theory. He seems to have rejected it for

Quaker Man.

habit of a Quaker-knee some years, but to have come at last to breeches, gray stockings and buckled something near entire appreciation of its shoes. He wore good broadcloth, with truth and its importance. Dalton him- spotless white neckcloth, and usually self, on the other hand, not only paid carried a handsome, gold-headed walkinglittle attention to the work of others, but cane. Above the average height, robust was sometimes stubbornly indifferent to and muscular, with a broad, expansive important conclusions reached by others. head, often compared to that of Newton, Gay-Lussac, for example, made experi- he was a singularly impressive figure. ments and reached conclusions of discov. When he visited King William at the ery which were not only important, but Court of St. James, and the king asked which afforded confirmation of Dalton's him how they were getting on in Manatomic theory.

chester, Dalton replied: “Well, I don't Gay-Lussac found that, under similar know—just middlin' I think,”and when circumstances of temperature and pres- rallied on the simplicity of this answer to sure, gases combine together in simple the king, he replied in his broadest Cumproportions by volume; as, for example, berland dialect: “Mebby sae; but what two volumes of hydrogen and one volume can yan say to sic like fowk.” of oxygen unite to form two volumes of Honors poured in upon Dalton in later water vapor. Yet Dalton refused to rec life. At the death of Davy, he was ognize Gay-Lussac's conclusions, in spite elected one of the eight foreign associates of their powerful support of his own view. of the French Academy. Berlin, Mu

He did in this what has been very com nich and Moscow equally honored him. monly done in the world of science, and At Oxford, in 1832, the degree of D.C.L. what is still done by men of the largest was conferred upon him, along with Miknowledge and even the highest genius; chael Faraday, David Brewster and Robhe made his own confidence in knowl- ert Brown. His own estimate of himself edge, and his own consciousness of power appears from what he once said to a in research, the ground of refusal to open young man: “Thou seems to have better his eyes to anything not known by him- talents than I possessed at thy age, but self. It is quite as common in science as thou may want the thing I had a good in theology or religion, for knowledge to share of—perseverance." Great hero as become so settled, so thoroughly estab he was of science, he was undoubtedly lished and so universally accredited as to greater still as a hero of self-culture.

CHOLERA IN THE LIGHT OF MEDICAL SCIENCE

NY one who will turn to so disease" applies to malignant cholera,

good an accessible authority and does not in the same way apply to as the article “Cholera," in simple cholera. And as in the case of the Encyclopædia Britannica, typhus, the origin of the disease is

may get a clear view of the from offensive conditions of life, yet the medical and scientific grounds for dis- typhus infection will no less strike the tinguishing between two forms of chol- clean and wholesome if they come in coneraic disease—“two distinct forms of tact with it, just so in the case of cholera; disease,” the article says:

although its infection is much easier to (I) “SIMPLE CHOLERA, called also escape, yet it may strike the clean as well European Cholera, British Cholera, and as the unclean if they are sufficiently exSummer or Autumn Cholera," and posed. It is from the author of the arti

(II) “MALIGNANT CHOLERA, called cle on cholera referred to above that we also Asiatic Cholera, Indian Cholera, Epi quote the comparison between typhus and demic Cholera, and Algide Cholera”“algide" referring to the collapse and Another fact of typhus, as a disease cold stage characteristic of this form of more dangerous than simple cholera, is the disease.

its violently infective character, and yet The distinction between simple cholera the comparative security of those who and Asiatic cholera is something like handle it if they know how to use proper that between typhoid and typhus; only care. The author just quoted says : simple cholera may be much more short of malignant than typhoid is short of

“In most large cities limited outbursts of the

disease occur from time to time, under the contyphus; and even very severe simple

ditions of overcrowding and poverty (unclean cholera may be, relatively to malignant overcrowding, it should be said, filthy habits of cholera, much easier to control and cure person, nasty bedding, bad food, as rotten fruit than severe typhoid.

and tainted meat, or the variously terrible diet

of starvation, which makes hunger-typhus one The distinction between typhoid and

of its worst types), although the increased fatyphus was first accurately made out no cilities for recognizing such outbreaks, and for longer ago than 1836, and not finally es- the prompt isolation or removal of infected pertablished beyond all doubt until Sir

sons to hospitals, operate in general effectually

to prevent any extensive spread of the fever. William Jenner, at the London fever

The disease appears to be communicated by the hospital, in the years 1849-51, made clin exhalations given off from the bodies of those ical and pathological observations which suffering from the fever, and those most closely clearly demonstrated the difference be

in contact with the sick are most apt to suffer.

This is shown by the frequency with which tween the two fevers, both in their symp

nurses and physicians take typhus from cases toms and in their origin. Typhoid is under their care (where proper precautions are bad enough, but typhus is pretty well un not practicable). As in all infectious maladies, derstood to be the more dreadful and

there is often observed in typhus a marked pro

clivity to suffer in the case of individuals, and dangerous malady, and if physicians and

in such instances very slight exposure to the the press were to make some few cases of contagion may convey the disease. Typhus is typhoid an occasion for a wild cry of highly contagious throughout its whole course "Typhus-Plague," the mistake would

and even in the early period of convalescence.

The contagion, however, is rendered less active discredit and disgrace all concerned in it.

by the access of fresh air; hence, this fever The corresponding mistake of taking rarely spreads in well-aired rooms, or houses simple cholera for Asiatic, and wildly where cases of the disease are under treatment. crying “ Asiatic Pestilence,” is none the

Although not unknown in warm countries, it

has most frequently prevailed in temperate or less a scandal and a shame because the

cold climates." newspapers and the medical authorities lend themselves to it.

In the case of cholera, whether simple It is interesting to note of typhus, com- or malignant, there is no infection from pared with typhoid, that “while typhus the persons of the sick ; not even from is a disease of overcrowding and poverty, their discharges, or soiled clothing, nor typhoid may occur where such conditions from the dead, provided always that no are entirely excluded.” In the same way needless exposure is ventured, and that much that is said of cholera as a “filth- the discharges and soiled clothing are at once disposed of, and on no account with these will cause cholera, it is yet allowed to stand and ferment; for by next to impossible to infect with these standing and fermenting they become except by means of contaminated water; dangerous from the exhalations of an and the common talk, as if the microbes infectious character which they will give were able to get out of the choleraic off.

fluids, to fly about, and to alight on peoIt is a singular fact that the existence ple and on their food, and so get into them, of typhus, with its much greater danger is nearly or quite pure imagination and of infection from the persons of the sick, utter foolishness. It is equally imaginawill not be used by the press to create a tive and foolish to suppose that a microbe scare, while at the mere name of cholera too small to be visible, and forming a of the common and simple character, parcel of cholera-poison so minute as which involves no danger whatever of to be revealed only by the microscope, infection from the sick, there may be a operates in a violent attack of cholera by wild cry of “Asiatic Plague." This is breeding other microbes, which make because experience has made typhus cholera-poison, and so cause the cholera familiar, and people have learned to deal sickness. It is far more probable that with it properly. They might equally when cholera-poison in considerable learn to take cholera sensibly, not only amount is taken in with the breath, or in without panic, but without any fear of water, and perhaps in both ways, some the presence of the sick, or of the dead. law of the system makes up more or less Not even in malignant cholera is there any of it into microbe-parcels, which are thus danger of contagion from the sick or from results of the presence of a poison, all the dead. The great and most urgent or most of which has been taken into necessity is for disposal of the discharges the system in the form of a volatile poison, promptly and effectually. One of the and not in the form of microbes. At any best authorities, Dr. Charles Creighton, rate an immense body of evidence goes in the Encyclopædia Britannica article to show that the general and ordinary form on quarantine, says of “Principles of of infective poison is that of a miasmatic Quarantine Against Cholera”:

exhalation, a volatile poison in the air,

which may be, and commonly is, taken "The peculiar dangers of cholera-diffusion

with the breath. arise from the vomited and purged matters which are characteristic of the malady. Under

The thing most important to note about certain circumstances the discharges of the sick

typhus is the miasmatic exhalations from are infective; they are probably not infective the persons of the sick and their violently as they come from the body; but even minute infective ciiaracter. It is not enough quantities of the choleraic matters, if they have fermented in the ground, or in boxes and bun

noted that persons may be a source of dles of foul linen, bedding or clothes, may

these typhus exhalations before they are exhale a virus which is often suddenly prose sick and without being sick, owing to an trating in its action. Thus every person with excessively foul condition into which they cholera, or even with choleraic diarrhea, in times of epidemic is a source whence many

have got and which they have become habmore may be poisoned (not from the persons

ituated to. An Egyptian convict-ship on themselves, but from the choleraic matters which there was no sickness brought an vomited or purged and not taken care of at epidemic of typhus to Liverpool in 1861, once]. When the choleraic matters percolate into wells or reservoirs the poisoning may be

clean people taking the infection by conon a great scale.”

tact with the well from the ship. In Feb

ruary of 1892 the New York health The fact of infection, where it takes authorities made a most deplorable exhiplace at all, by means of poisonous ex- bition of ignorance of the generation of halations, or by choleraic matters con- typhus in the case of a lot of Russian taminating water, is of peculiar signifi Hebrews who arrived in the Massilia, Jancance as showing a cholera-cause other uary 30, after a voyage of twenty-eight than microbes. The very common ref- days, without any death or any sickness erences to a cholera-microbe are calcu from typhus, but some of whom came lated to mislead. They are not according down with typhus February 11. We canto fact. Granting the existence of mi- not fully deal with the matter here, but crobes, which, though the merest invisible will merely state the simple fact that on microscopic things, form a parcel of chol- the first of March the health authorities era-poison, and that water contaminated had 102 persons packed into one lodginghouse, out of which they had sent fifty- excreted by organs of excretion and by three typhus cases, all developed in the the lungs and the pores of the skin. A house. At this date the place was cleared principal office of a good liver is that of and the plague checked. A more scan stopping poisons in the blood brought to dalous making of a poison-den could not it by what is known as the portal vein. have been contrived. A reporter and Some it destroys and some it stops and two policemen, who orce or twice entered sends off in the bile to be cast out by the the house, sickened and died. From bowels. Dr. T. Lauder Brunton says, February 11 to March 5 there had been in a recent volume of lectures entitled 137 cases and nine deaths, nearly all of “An Introduction to Modern Therapeuthem due to crowding the suspects into tics'': lodging-houses in the city. Yet even the knowledge which we have gained dur. then, when proper measures were taken, ing the last few years regarding the poisonous the sickness was checked, and no panic properties of some albuminous substances, and was raised meanwhile, although some

of the products which albumen yields when

decomposed, makes it, as Mr. Darwin once said effort in that direction was made.

to me, a wonder that we are all alive, considerThe point we wish to make plain here is ing how many poisonous substances are conthe comparative safety of the public in stantly formed in the intestines. Indeed, one presence of so infective a disease as

can hardly see how life would continue long

were it not that the liver has a position and typhus. Serious as the infection may be,

function like the gatekeeper of a castle in time its character can be greatly modified by of war, inspecting all comers, and turning back proper care. Dr. Murchison said: “If a those that are dangerous. It possesses a twopatient be placed in a large, well-venti

fold power to prevent poisons entering the portal

vein from passing into the general circulation, lated apartment, the attendants incur lit

for it turns back some and destroys others. tle risk, and the other residents of the Some are simply arrested and excreted by the same house none whatever." Dr. Austin bile, and finally ejected from the body. Some Flint held the same view, although his

it has the power of actually destroying, or, at

any rate, converting them into non-poisonous very long experience covered some years

compounds. Organic poisons appear to have of prevalence of the disease in one of the their activity lessened in the liver by combinahospitals, the condition of which could not tion with glycogen. Leucomaines [alkaloid be made properly wholesome. Wherever

poisons) are formed in the tissues generally,

and an increase of glycogen in the blood [from entire cleanliness and good ventilation are

food, as milk, supplying it] may combine with secured, typhus cases in a hospital do poisonous products in the nerves and muscles, not create danger for either the attend- preventing them from exerting a poisonous acants, the physicians or students inspect

tion, and thus removing weakness, languor, or ing the sick. In the case of the Russian

tremor due to them.” Hebrews in New York, whose systems The “ volatile poisons excreted from had been breeding typhus-poison from the lungs and skin," says Dr. Brunton, their starvation diet in Russia, their help to cause the bad effect of foul air. hardships of travel and their voyage of They will, in fact, though very subtle and twenty-eight days, shut up in stormy volatile, and in very small quantity, rapweather in the steerage of a ship, the idly make the air of a close room foul. very great probability is that if, in a place They become also a deadly virus in the securing abundance of good air, they had sweat and grime accumulated on the skin been thoroughly cleansed with warm and the clothing of the unclean ; and a alkaline bathing, their garments steamed great number of facts prove that when and cleaned, or replaced with new of these poisons are retained in the system, proper warmth, and a good diet of hot by any failure of excretion or by excess soups, nice bread and some fruit been of production, or are taken back into the given them, not a single case of typhus system with the breath, the results may would have been developed.

be of the worst typhus, or at least typhoid, On the other hand typhus can be de- character. In the case of the Black Hole veloped without any contact of the vic- of Calcutta, where 146 persons were contims with infection. The chemistry of fined in a room twenty feet square, with the healthy system is all the time pro- only two small windows for air, 126 died ducing a variety of poisons, especially in over night, and of the twenty-three who the intestines, but to a degree all through remained alive, says Dr. B. W. Richardthe system. In healthy persons, under son, “nearly the whole suffered afterwholesome conditions, these poisons are ward from what was called putrid typhus,

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