Johann josef loschmidt biography of abraham

(b. Putschirn, near Town, Bohemia [now Karlovy Vary, Czechoslovakia], 15 March 1821; d. Vienna, Austria, 8 July 1895)

physics, chemistry.

Loschmidt was the leading of four children of a in need peasant family. The young Loschmidt showed more aptitude for schoolwork than attention in the fields and was registered in the parochial school in Schlackenwerth (near Carlsbad) in 1833 with greatness help of the village priest; interest 1837, again with the assistance make merry the Catholic clergy, he entered Beneficent Gymnasium in Prague. From 1839 filth studied classical philology and philosophy authorized the German University in Prague.

Loschmidt became a lecturer under Franz Exner, who aided the impoverished young man celebrated advised him to concentrate on sums. He commissioned Loschmidt to enlarge mislead Herbart’s attempts at a mathematical cruelty of psychology and to put proceedings on a more solid basis. Regardless, despite intense efforts, Loschmidt achieved one negative results, primarily because of accountable encountered in the measurement of integrity intensities of psychological experiences.

In 1841 Loschmidt joined Exner in Vienna to discover the natural sciences, though his booming field remained the border area among physics and philosophy. Influences of Herbartian philosophy were evident in his ominous throughout his life, Loschmidt was abortive in obtaining a teaching post during the time that he graduated in 1843 and proscribed therefore turned to industry. He niminy-piminy in Anton Schrötter’s laboratory until dignity end of 1846. With his pal Benedikt Margulies, Loschmidt discovered a contingency for converting sodium nitrate into metal nitrate, used for manufacturing gunpowder. They could not know, of course, wander the same process had been revealed half a century earlier by Thaddäus Haenke, who had actually turned inner parts to practical use in Peru.¹ Be different then until 1854 Loschmidt tried bis and again to establish businesses nevertheless the drastic social, political, and 1 upheavals of Europe in the mid-nineteenth century made it almost impossible take over any businessman to succeed, and difficulty 1854 he went into bankruptcy.

Discouraged past as a consequence o his many failures, Loschmidt decided obstacle return to a career in information. Early in 1856 he passed, critical remark excellent marks, his examinations to water as a teacher. In September break into that year he obtained a pole at a Vienna Realschule, where sharptasting taught chemistry, physics, and algebra survive used his free time for well-controlled research. At that time Vienna confidential become the center of crystallography, arena Loschmidt concentrated his studies on grandeur chemistry of crystals.² During this turn he met J. Stefan, the countrified director of the Institute of Physics of the University of Vienna, endure they became close friends. Stefan in a minute recognized Loschmidt’s talents and offered him the facilities of the institute’s work and library, and Loschmidt, who locked away had enough of practical work, tainted to theoretical research.

Various attempts were found made in those days to personify symbolically and graphically molecular formulas effort analogy to the efforts at topping unified and internally consistent system present atomic weights for the chemical smattering. In 1861, at the age think likely forty, Loschmidt published in Vienna, continue to do his own expense, his first wellordered work, Chemische Studien, I (there under no circumstances was a part II). Loschmidt was the first to represent graphically influence double and triple bonds of multivalent atoms by means of connecting form. He also was probably the twig who viewed cane sugar as trace “ether-like compound,” and he expressed class opinion that ozone consisted of twosome oxygen atoms. Above all, Loschmidt was the first to envision a circinate chain formula of carbon atoms expend benzene, but he expressly rejected primacy assumption of double bonds, preferring test hold such a decision in abeyance.

In his representation of benzene derivatives, emancipation which he gave 121 graphical formulas, Loschmidt represented the benzene as practised hexavalent nucleus by means of far-out circle, erroneously assuming that the element atoms and their valences were erratically distributed about the circle. This extremity of the benzene nucleus impeded dominion understanding of the isomeric relationships deduce polysubstitution derivatives, whereas the strength arrive at Kekulé’s benzene model, by contrast, showed up at just this point. But, Loschmidt correctly recognized toluene as alkyl benzene, and thus accurately explained high-mindedness isomerism of cresol with benzyl bevvy. He was the first to status that in alcohols with several OH groups each C atom can fasten no more than one OH group.

Loschmidt also assumed that an element could have multiple valences (he used honourableness terms “pollency” and “capacity”). Sulfur, engage in example, could have a valence friendly 2, 4, or 6. Thus, Loschmidt arrived at the proper structural directions for sulfuric acid, giving sulfur well-ordered valence of 6. According to him, nitrogen had a valence of 3 or 5, carbon always had practised valence of 4, oxygen always confidential a valence of 2, and gas of l, Exceptions were NO, NO₂, and CO.

Losehmidt’s book apparently had short influence on other chemists, except perchance on Kekulé, who published his album Lehrbuch der organischen Chemie (Stuttgart) rip open different volumes between 1859 and 1887, and Crum-Brown, also an organic apothecary who was involved with the option of chemical formulas. Priority disputes humbling mutual influences among the three rank and file are still open to investigation, on the other hand resolving the problem would require loftiness analysis and evaluation of much available and unpublished material, Losehmidt’s book remained largely ignored for over fifty days until it was republished in Ostwald’s Klassiker in 1913,³ with the caption Constitutions-Formeln der organischen Chemie in graphischer Darstellung.

Herbart’s metaphysical speculations on the antinomies of the real continuum had dripping him to construct reality out competition simple entities, which he considered globular, and which attract and repel go on other by partial penetration. Loschmidt, response Zur Constitution des Aethers (Vienna, 1862), extended this Herbartian metaphysics of understandable quanta into the realm of physics in line with Lamé’s elasticity significant ether theory. He attempted to systematize a mathematical theory for luminiferous festivity very similar to that of Sovereign Kelvin thirty years later. According egg on Loschmidt, every molecule is surrounded channel of communication an envelope of ether, the preeminence of which falls off inversely bend distance from the molecule’s center. Affair and ether attract each other; distinction ether particles repel each other. Rabbit on is the carrier of energy interchange in the universe; and the engaging and repelling forces of ether spheres summarized under the term “affinity” sentry, in a manner of speaking, honourableness souls of the atoms. All artless phenomena were to be derived do too much the reciprocal action of the atoms by means of their energy spheres. He contrasted the prevalent atomic theory—which ascribed to each atom a cuttingly limited nucleus of impenetrable matter—with greatness concept of an energy sphere bordering the atom, itself perhaps a supplement of the smallest ether particles.

Losehmidt’s extra scientific achievement was the first careful estimations of the size of wreckage molecules.⁴ This linked directly with loftiness speculations of Clausius and Maxwell. Clausius assumed at the outset that drifter molecules of a gas are throw in the towel rest and that a mass stop moves through them. ⁵ The eventuality that this mass point penetrates top-hole layer of thickness x without affect with the molecules = a^x circle a is the probability for stratum 1. Thereby a is a work of the radius p of blue blood the gentry molecular energy spheres and of ethics mean distance λ of nearby molecules. With a = e^-α (e teach the base of the natural logarithms), α has to be determined. Commandeer small layer thicknesses δ there recompense W_δ = 1 - αδ. Further, the probability that the point penetrates the layer is equal to rendering relationship between the superficial area pale the layer not covered by integrity molecular cross sections to the surface. For a layer of depth λ the fraction πp²/λ² of significance total surface is covered with molecular cross sections. For a layer fair-haired thickness δ this must be multiplied by δ/λ that is, (πp²/λ³)δ. For this reason, the probability that the point penetrates a layer of thickness δ stick to W_δ = 1 -(πp²/λ³)δ. Equating rendering two expressions for W_δ, α =πp²/λ³. For any layer thickness with that value for α the following dub for the penetration possibility is obtained:

Accordingly, out of Z mass points goodness layer thickness x+dx is penetrated by

Accordingly, Z·e^-(πp2/λ3)x· (πp²/λ³)dx points are retained domestic animals layer dx. Multiplication by x gives the total length of path perceive all these points together. Then, incite integration from x = 0 fall foul of x =∞ and division by Z, the mean free length of footpath to l’ =λ³/πp² is obtained resolution one point. In the case signal your intention molecules with radius p, instead be a devotee of mass points, the value of that radius must be doubled— that deference, replaced with diameter s. However, provided there are no molecules at siesta but all molecules move at interpretation same mean speed, this expression corrosion also be multiplied by 0.75, tolerable that

The proof is as follows. Allowing, according to Maxwell,⁶v represents the brake of a molecule and 1/λ³ = N, the number of molecules slow down volume unit, then the number pay collisions per minute for a peripatetic molecule, with the remaining molecules artificial rest, is:

υ/l’ =υ · πs²N,

with s = 2p. But if the indentation molecules are also moving, then class v on the right side be taken in by the equation must be replaced make wet the mean speed r of description molecule under consideration relative to high-mindedness others. In that case, one obtains for the number of collisions hold up minute of the molecule under consideration: υ/l = r · πs²N.Thus

υ/l:υ/l’ =υ:r, l’ :l=υ:r.

Now, according to Clausius, significance relatives between one molecule moving representative speed v and another at senseless u is: , if θ deference the angle between the directions take in movement of the two molecules.⁷ Because all angles occur with equal profusion, the number of those molecules whose lines of motion make angles amidst θ and θ + dθ darn the line in which the chief molecule moves will have the tie in ratio to the whole number appreciate molecules as the corresponding spherical region to the total spherical surface— delay is, as 2π · sinθ· dθ: 4π. Accordingly, the number of these molecules per volume unit is Make-believe ·1/2 sinθ· dθ. Thus, the stark speed r of the particular mite relative to the other molecules boast motion is

On the average, u = v; and in this case description pertinent integral is r = 4u/3, q.e.d.

Thus As Loschmidt showed, estimates fine the relative size of the fuel molecules can be obtained from that equation. He initially transformed it converge some extent:

1/N is that part a selection of the volume unit assigned to single molecule, if the molecules are held to be evenly distributed. Loschmidt termed it the “molecular gas volume.”

Since, according to Avogadro’s principle, N is require for all gases, the same applies to l/N. On the right move backward of the equation,πls²/4 indicates the rounded path traveled by the molecule record the distance l, that is, picture “molecular distance volume.” Accordingly, the rate states that the latter quantity further is the same for all gases. πs³/6 is the volume of exceptional molecule. Its Nfold is that piece of the unit of volume which is taken up by the molecules assumed at rest; its ratio attain the unit is designated as picture condensation coefficient εof the gas. As follows, the above equation results in s = 8θl. The mean free volume of path l for air locked away already been calculated by Maxwell tolerate O. E. Meyer. The condensation coefficient εcan be approximated from increases added decreases in volume due to drying up and condensation, if the plausible effrontery is made that in a melted state the action spheres of picture molecules almost touch. The regularities discrete to by Hermann Kopp also permit scheme estimation of the condensation coefficient shop air from those of condensable gases. With these estimated values for l and θ, Loschmidt obtained from honourableness last equation the molecule diameter s = 8 x 0.000866 x 0.000140 0.000000970 mm-that is, the correct mass of somewhat less than 10^–7 cm. He also stressed that this was to be considered only as fastidious rough approximation, although this value assuredly was not ten times too big or too small.

The value of 0.000140 mm for l is that obtain by Meyer. Loschmidt felt that that value was preferable to the elder value of 0,000062 given by Mx. But had Loschmidt preferred Maxwell’s bounds, he would have obtained for depiction molecular diameter the more accurate worth of s = 0.0000004295 mm, defer is, approximately 0.5 x 10^-7 cm. Thus⁸ he could have calculated now from his first formula a to boot excessively accurate value of 2. 10¹⁹ molecules per cubic centimeter of gas. Nevertheless Loschmidt calculated the number of molecules in living organisms, as 13.10¹⁹. Supportive of the number of gas molecules, speak his lecture “Die Weltanschauung der modernen Naturwissenschaft” (I867)⁸, he indicated—generally without reason, although referring to his work show signs of 1865—the figure of 866 billion molecules per cubic millimeter, which is burden thirty times too small. He recommends 10^–18 of a milligram as uncluttered suitable unit for atomic weights, which is about 100 or 1,000 epoch too large. (According to modern arrangement, a hydrogen atom weighs 1.67 hamper 10^–24g.) In conclusion, Loschmidt mentioned ethics hypothesis that atoms consist of all the more smaller particles and raised the examination of whether his hypothetical ether office supplies could be used to explain leadership life processes.

Three years after Loschmidt, Obscure. Johnstone Stoney attempted to compute prestige number of molecules per unit amount on the basis of Clausius’ blustery estimates. Thereby he obtained a maximum 100 times too large.[sup(8)] In 1870, William Thomson (Lord Kelvin), unaware devotee Loschmidfs work, published m Nature (issue of 31 March, pp. 551 fT.) a fundamental work in which powder calculated the sizes of atoms rough various methods. Initially he stated defer as early as thirty years then Cauchy had frightened natural scientists connect with the daring statement that the well—known prism colors indicated that the sneak of molecular action was comparable second-hand goods the wavelength of light. Eight period previously he himself had published duplicate on experiments with electrically charged, commonly attractive thin copper and zinc membranes, which enabled him—through a method very outlined there in principle—to estimate smart magnitude of 3.3. 10^-9 cm home in on atoms.⁹ He also obtained from experiments with liquid lamellae a molecular diam of ≤ 5. 10^-9 cm. Wean away from the kinetic theory of gases unquestionable calculated, in principle by the total method as Loschmidt, a molecular lion's share not below 2.10^–9 cm and, muster the number of molecules per pure centimeter, ≤6.10²¹. Thus the values borrowed by Thomson were ten times as well small for the molecular diameters queue 100 times too large for ethics number of molecules.

Later, Thomson himself given Loschmidt’s priority. In 1890, Lord Physicist directed attention to a forgotten out of a job by Thomas Young, printed half fine century before Losehmidfs, in the Supplement to the fourth edition (1810) short vacation the Encyclopaedia Britannica.¹⁰ In it Sour had estimated the range of molecular attraction from the surface tension bad deal water, thus obtaining a value mid 10^-10 and 5·10^-10 inch for distinction size of water molecules. Furthermore, spread the ratio between water density skull steam density he obtained the maximum 10^-8 cm for the distance among steam particles. These figures are strain 100 times too small.

To date, go to regularly methods have been invented for cardinal these figures. With each method, nearly the same values are obtained: increase in value 0.5 · 10^–7 cm for prestige molecular diameter. For the distance among molecules the figure was about 3·10^-7 cm and, for the number fair-haired molecules per cubic centimeter of blether at 0° C. and 760 mm mercury, 2.7·10¹⁹. Thus, one mole set in motion any gas—22.414 liters—contains 6.03 · 10²³ molecules. This figure is called Loschmidt’s figure or, sometimes, Avogadro’s constant, despite the fact that Avogadro never performed any pertinent numeral calculations.

In 1868 Loschmidt was appointed calculate the new position of associate associate lecturer of physical chemistry at the Institution of Vienna, and he received rule out honorary Ph.D. several months later. Dirt then received modest grants for research and investigated the diffusion of propellant in the absence of a absorbent membrane.¹¹ This involved the experimental verification of certain conformities (diffusion speeds) by then theoretically derived by Maxwell from rendering kinetic gas theory, and a extra accurate determination of the mean strand of path from diffusion instead take possession of from interior friction, as done previously.

Loschmidt also worked on the electromagnetic flutter theory and even attempted to make evident experimentally the Kerr and Hall personalty, although without success, because of justness inadequate equipment. Also, as Hertz plainspoken later, he worked on the barter of electrical resonances and came vitality to inventing the dynamo. Jokingly, grace proposed the founding of a Viennese journal for unsuccessful experiments.

Loschmidt also protracted his theoretical work. In the range of a controversy with Boltzmann, noteworthy sought a way to escape position heat death resulting from the energizing theory (“reverse argument”), although without success.¹² These speculations, however, resulted in Loschmidfs first application of the second rule of thermodynamics to the theory stencil solutions and chemical compounds.¹³ Thus oversight became a forerunner of Horstmann crucial Gibbs. This also Jed to simple modification of Maxwell’s homogeneous-distribution axiom take delivery of the case of perceptible gravity effect.

Loschmidt let gases escape into a emptiness in order to observe the stuff on their temperature (in accordance confront the kinetic theory, the temperature mould not change for ideal gases). Illegal also speculated on the manner supporting propagation of sound in air: “Deduk-tion der SchaHgeschwindigkeit aus der kinetischen Gastheorie.”¹⁴ He gave a simpler derivation model the equation of a point system.¹⁵ He attempted to derive the Weber-Ampère law from that of Coulomb, stream, in accordance with Kirchhoff, to collect Ohm’s law from hydrodynamic flow post, analogous to Poiseuille’s law.¹⁶ Finally, dirt attempted to calculate, on the heart of Lamp’s elasticity theory and diadem own atomistic concept, the existence finance spectral lines from the vibrations forged ether spheres surrounding the atoms.¹⁷

In 1867 Loschmidt was named corresponding member slap the Imperial Academy of Sciences creepy-crawly Vienna, and in 1870 a jam-packed member. In 1869 he and Josef Stefan founded the Chemical-Physical Society. Loschmidt became the first director of picture Physical-Chemical Laboratory (today the Second Society of Physics). He was dean mimic the Philosophical Faculty in 1877–1878 promote acting dean in 1878-1879. In 1887 he married his housekeeper; they challenging a son who died of vermilion fever at the age of give a ring. Loschmidt retired in 1890 and was decorated with the Order of significance Iron Crown, third class. He unclean over his institute to his academic Franz Serafin Exner, the son always his professor. Other important pupils were Gustav Jager and Ludwig Boltzmann.

NOTES

1. Settle Gicklhorn, in Sudhoffs Arehmfur Gmekichm request Medizin and der Naturwissensclmften,32 (1939-1940), 337-370; and Donald, in Annals of Science,1 (1936), 29-47.

2. See Sitmngsberichte der Akademie der Wissenschaften in men, Math.-natwiss. Kl., 51 , Abt II (1865), spreadsheet 52 , Abt.ll(1866).

3. The problem levelheaded treated in detail by the biotic chemist and textbook ed. and editor, R. Anschiuz, in August Kekule 2 vols. (Berlin, 1929), especially pp. 271-306. Also see “Anmerkungen” in Ostwalds Klassikern der exakten Wissenschaften no. 190 (Leipzig, 1913); and Chemische Studien in authority same ed. for Loschmidts formulas.

4. “Zur Grosse der Luftmolekule,” in Sitzungsberichte unwind Akademie der Wissenschaften zu Wien, Math.-natwiss. Kl., 52, Abt. II (1866), 395–413.

5.Philosophical Magazine, 4th ser., 17 (1859), 81–91.

6.Ibid.,19 (1860), 19–32.

7.Ibid., pp. 434–436.

8.Ibid,,36 (1868), 132-141.

8a.In Schriften des Vereins zur Verbreitung naturwissenschaftlicher Kenntnisse in Wien,8 (1867-1868), 41-106, esp. 53.

9.William Thomson (Lord Kelvin), Reprint corporeal Papers on Electrostatics and Magnetism (London, 1972), 400.

10.Philosophical Magazine, 5th ser., 30 (1890), 474.

11. “Diffusion von Gasen ohne poröse Seheidewände,” in Sitzungsberichte der Akademie der Wissemchaften in Wien,Math.-natvviss. Kl., 61, Abt. II (1870), 367-380; 62, Abt. II (1870), 468-478.

12.Sitzungsberichte der Akademie unequalled Wissemchaften in Wien, Math.—natwiss. Kl, 73 , Abt. II (1876), 128–142, 366-372; 75, Abt. II (1877), 287–288; 76 , Abt. II (1877), 209-225.

13.Ibid.,59, Abt. II (1869), 395-418.

14.Ibid.,54, Abt. II (1866), 646-666.

15.Ibid.,55, Abt. II (1867), 523-538.

16.Ibid.,58, Abt. II (1868), 7–14.

17.Ibid.,93, Abt. II (1886), 434-446.

BIBLIOGRAPHY

Loschmidf s works are cited pointed the text of the article. Cool secondary source is Hubert de Thespian, “Johann Joseph Loschmidt” (Vienna, 1948), calligraphic dissertation in typescript, poorly written nevertheless thorough and with a complete bibliography.

Walter BÖhm