ALEXANDER SMITH, THE INVESTIGATOR* RALPH H.
MCKEE,COLUMBIA UNIVERSITY. NEW YORKC~TY
A s an investigator Alexander Smith brought an exceptionally clear and orderly mind to the interpretation of relatively simple experimental work. There eventuutedfirst a series of investigations i n organic chemistry, second a series i n the then newfield of inorganic physical chemistry, andfinally a group of investigations which involved devising a number of n m instruments and tools for use i n physical chemistry. The results of his epoch-making work on elemental sulfur are discussed i n some detail.
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Alexander Smith was horn September 11, 1865, in Edinhurgh, Scotland. He received his bachelor's degree from the University of Edinhurgh in 1886. He was a student a t the University of Munich simultaneously with Dr. W. A. Noyes of the University of Illinois. After the work which Smith did with Claisen a t the University of Munich, which led to his receipt of the degree of Doctor of Philosophy in chemistry, he served as assistant in chemistry a t the University of Edinburgh for one year. During the perior 1890-94 he was professor of chemistry and mineralogy a t Wahash College. In 1894 he came to The University of Chicago as an assistant professor of chemistry. He was associate professor of chemistry 18951903 and professor of chemistry from 1904 until he left The University of Chicago in 1911. During two years of this period he was dean of the Junior Colleges. In 1911 he left The University of Chicago to become professor and head of the department of chemistry a t Columbia University where he remained until illness compelled him to retire. His death occurred in Edinburgh in 1922. Dr. Smith was a member of the National Academy of Sciences and an honorary member of the Spanish Society of Physics and Chemistry. In 1911 he was president of the American Chemical Society. In 1912 he received the Keith Prize and Medal from the Royal Society of Edinburgh. You may recall that this prize is one of the oldest endowed prizes, as it has been established more than a century. In 1919 he received the honorary degree, LL.D., from the University of Edinburgh. Smith's first t e i publications of research work were on organic chemistry and mostly in German. They largely dealt with ketones and condensation reactions from ketones. These were dated 1890-1902. In 1902 his interest changed and his researches were in the applications of physical chemistry to inorganic chemistry problems. The period 1902 to 1909 was concerned with clearing up the inconsist~nciesin the observed data on sulfur and finding why they did not fit the theories of physical chemistry. The period 1909-11 was devoted to a study of vapor pressures and * Presented a t the dedication exercises of the George Herbert J~nesLaboratory of The University of Chicago, December 16. 1929. 247
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devising instruments which permitted rapid and accurate vapor pressure determinations to be made. In the period 1912-19 Dr. Smith's interest turned to the study of dissociation pressures and related phenomena. Unlike most university men, Dr. Smith excelled in three phases of investigation, all of which have added distinctly to the chemical knowledge of the world. He gave us a new method of teaching chemistry but this I shall not discuss in this paper. He gave us new instruments and tools useful for the study of chemical problems. I shall discuss these further. Thirdly, he gave us new facts and ideas in the field of organic chemistry and also outstanding discoveries both in facts and in methods of approach in the field of physical chemistry as applied to inorganic compounds. Viewed in large perspective, the burner of Burisen, the condenser of Liebig, the spectroscope of Kirchhoff, are high points in the history of the development of chemistry. A generation later, will those who look back upon the history of chemistry in this country view the glass bulblet Smith used for boiling-point determinations, the dynamic isoteniscope, and the static isoteniscope as similar outstanding developments? Perhaps they will include the work of his pupil, Freas, on thermostats and ovens largely developed during the period of his association with Dr. Smith. The development of a new tool often permits a science to advance in a direction where before progress was impossible. The use of the isoteniscope gave us a new method of determining vapw pressures a t elevated temperatures as well as a new method of determining dissociation of such materials as *' mercurous chloride, ammonium halides, phosphonium iodide, phosphorus pentachloride, calcium carbonate, etc. Smith proved that the vapor of calomel is not either HgCl or HgzClzbut is a quantitative mixture of equal volumes of mercury (Hg) vapor and mercuric bichloride (HgC12) vapor. He further showed that the common assumption that the dissociation of ammonium halides is complete is very far from being correct; similarly that phosphorus pentachloride is dissociated only a few per cent (4 per cent) between the temperatures of 110' and 160°C. and is less dissociated a t lower temperatures. Most of the researches of Smith were carried out by himself and an assistant. Some were carried out with students. Menzies, Hale, Ransom, Eastlack, and Scatchard were assistants. Holmes, Freas, Carpenter, Carson, Brownlee, Hall, Lombard, and Calvert were students working for the doctor's degree. McCoy and Kendall were associates a t Chicago and a t Columbia University, respectively. The brief discussion which I now present does not permit me to bring out the part that each of these men, then young, had in the work that they did with Dr. Smith. It is sufficient to recall that each of these has reached a place of honor in our beloved science. The training which they received with Dr. Smith was no small
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influence in bringing about their respective achievements. Each one of them holds the friendship and guidance which Dr. Smith gave him as among his most valuable experiences. In the time available it is possible to discuss in outline only one of the more important researches of Dr. Smith. I have chosen to give particular attention to his work on sulfur. It had long been known that there were several forms of crystalline sulfur and that sulfur when first melted was quite limpid but a t a temperature of about 170° became viscous and a t still higher temperatures again became limpid; moreover, that on sudden cooling from temperatures above 170°, there was found mixed with the crystalline sulfur soluble in carbon bisulfide, an insoluble amorphous sulfur. In 1902 Smith showed that the amorphous sulfur was but a supercooled form of liquid sulfur present in melted sulfur above 170°C. and further that this amorphous insoluble sulfur was molecularly like the common rhombic crystalline sulfur which is soluble in carbon bisulfide for in each case the sulfur molecules carried eight atoms of sulfur in the molecule. He next showed that the transition of the melted rhombic sulfur, which we call sulfur-X, into the liquefied amorphous sulfur, sulfur-p, is an endothermic change. And, as he showed by viscosity measurements, this transformation begins as early as 159.5'C. Moreover he proved, contrary to the common belief, that this transition point does not vary with the previous history of the sulfur. By the use of simple experiments depending upon solubility and an ingenious but perfectly sound argument, he showed that sulfur-X and sulfur-p are chemically two different substances though each has the formula ST. These determinations of the solubility curves of sulfur-X and sulfur-p in melted triphenyl methane, and the inferences to be drawn therefrom, are excellent examples of the acute observation and clear logic for which Smith was recognized by all who knew him. He further showed that the two liquid states of sulfur are partially, but only partially, miscible, sulfur-X predominating below 160' and sulfurp above 160'. He showed that the solubility of sulfur-p in sulfur-X a t 160' is about 12 per cent. The maximum yield of sulfur-p as shown by the amount of amorphous sulfur obtained when chilling from an elevated temperature was found to be approximately 62 per cent of amorphous sulfur and occurs in the presence of about 2 per cent iodme. Smith called attention to the fact that when one acidifies a sodium thiosulfate solution the sulfur precipitated is a t first in fluid drops and later gives 100 per cent amorphous sulfur, i. e., sulfur insoluble in carbon bisulfide. Smith showed that many materials, besides iodine, facilitate obtaining amorphous sulfur from melted sulfur, the simplest of these being sulfur dioxide which is itself formed when ordinary sulfur is melted in con-
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tact with air. On the other hand, there are a number of other materials, particularly gases such as ammonia, hydrogen sulfide, and carbon dioxide, in whose presence the yield of amorphous sulfur on chilling molten sulfur from an elevated temperature is insignificant. Many methods of cooling and of heating and many reagents were tried but the final result was that agents such as iodine, oxygen, sulfur dioxide, hydrogen halides, etc., are catalytic agents which slow down the speed of change of sulfur-p to sulfur-A. On the other band, in the presence of ammonia, hydrogen sulfide, carbon dioxide, etc., the speed of .change of sulfur-p to sulfur-A is so rapid that only crystalline rhombic sulfur is obtained by rapid chilling of the molten sulfur through which these gases have just been bubbled. From the foregoing we see that the two liquid forms of sulfur are dynamic isomers, a relation of which there was some suspicion before Smith and his co-workers took up their investigation but for which no proof of importance had been adduced. The clearing up of this matter also settled previous disputes on the relations of the insoluble amorphous solid sulfur and the soluble crystalline solid sulfur. To complete the study of sulfur, precipitated sulfnr was studied in detail. As has been mentioned before, sulfur precipitated from an aqueous solution of sodium thiosnlfate on acidification is in the form of droplets of liquid amorphous sulfur. These droplets change rather quickly to crystalline soluble sulfur of the ordinary type. This change occurs in the presence of weak acids, neutral salt solutions, or alkaline solutions. In the presence of strong acids the percentage of amorphougsulfur remaining in the product is essentially proportional to the concentration of the acid, that is, in a low pH medium considerable amorphous sulfur is found along with the crystalline soluble sulfur. The improved understanding of the relations of the various forms of sulfur brought about by the investigations just outlined made it imperative and comparatively easy to determine exactly the true melting points of the various forms of sulfur in pure condition. This was done and the sulfur investigation made a completed whole. Smith's eyes were strikingly clear and piercing. They were but the outward manifestation of a clear and piercing intellect. The life of Alexander Smith was a wonderful life. Through it all he never lost his natural love of the land of his birth, of his alma mater, or of the clear and piercing logic of its scientific leaders. There are more than seventy-five publications, including editions, to which the name of Alexander Smith is attached. In the bibliography given below these have been divided into two groups, one dealing primarily with publications of investigations, the other with educational books and papers.
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Bibliography I (I) "On Desylacetophenane," J . Chwn. SOL,Proc.. 57, 643-52 (1890). ( 2 ) - AND CLAISEN.L.. "Beitraae zur Kenntnis der 1.3-Diketone.-Ueber die Einwirkung von ~enz&hlorid auf die Alkalisalze dei Acetylacetons und des Benzovlacetons" (bearbeitet zum Teil in Gemeinschaft mit A. Smith). Ann.. 277, 184-206 (1893). Ph.D. Thesis. (3) "Ueber Kondensation mittels Cyankalium," Bcr., 26, G(t5 (1893). ( 4 ) "Ueher die Kondensation von Aceton mit Benzoin mittels Cyankalium." ibid., 26, 6571 (1893). J. H., "On Two Stereoisomeric Hydrazones of Benzoin," Am. (5) - AND RANSOM, Chem. J., 16, 108-15 (1894). (6) auf 1.4-Diketone." , , "Ueber die Einwirkune - von Hvdrazin und von Pbenvlhvdrazin . . Ann., 289, 31(t37 (1896). of Benzoin." Am. Chenz. J . . 22. 198-207 (1899). (7) . . "On the Phenvlhvdrazones . . . . (8) "On Potassium Cyanide as a Condensing Agent," ibid., 22, 249-56 (1899). (9) - AND MCCOY,H. N., "Notizen iiber die Einwirkung von Phenylhydrazin auf einige 1.4-Diketone," Bn., 35, 2169-71 (1902). (10) -AND HOLMES,W. B., "Ueber den amorphenSchwefel,"ibid.,35,299%4 (1902). (11) "Amorphous Sulphur and Its Relation to the Freezing Point of Liquid Sulphur," Roy. Soc. Edinbfwgh, Proc., 24, 299301 (1902). (12) "On Causes Which Determine the Formation of Amorphous Sulphur," ibid., 24, 342-3 (1902). (13) -AND H ~ L M EW. S , B., "Ueber amorphen Schwefel. I . Ueber den Einfluss drs amorphen Schwefels auf dem Gefrierpunkt des fliissigen Schwefels." Z. physik. Chem., 42, 469-80 (190243). Decennial Pub. of Univ. of Chicago, 9, 1902, Separate of 12 pp. (14) HOLMES. W.B.. AND HALL.E. S., "Ueher amomhen Sch"efel. 11. Ueber , -AND zwei fliissige Aggregatzustinde des Schwefels, SAund Sw und deren Ueberganpspunkt," 2. p h y i k . Chem., 52, 602-25 (1905); J . ' A ~ . Chem. Soc., 27, 797-820 (1905). (15) - AND HOLMES,W. B., "Ueber den amorphen Schwefel. 111. Ueber das Wesen des amorphen Schwefels und die Einfl"sse fremder Korper auf die Vorgtinge hei der Unterkiihlung geschmolzenen Schwefels." Z. physik. C h n . , 54, 257-92 (190546). (16) - AND CARSON, C. M., "Ueher den amorphen Schwefel. IV. Weitere Untersuchung der beiden Fomen des flussigen Schwefels als dynamiscber Isomeren," ;bid., 57, 6 8 W 1 7 (1907). (17) - AND CARSON,C. M., "Ueber den amorphen Schwefel. V. Das System Schwefel-Jad," ibid., 61, 200-8 (1908). (18) - AND BROWNLEE, R. H., "Ueber den amorphcn Schwefel. VI. Gefjllter Schwefel," ibid.,61, 209-26 (1908). (19) - AND AfENzres, A. W. C., "Solubilities of Orthophosphoric Acid and Its Hydrates. A New Hydrate." J . Am. Chem. Soc., 31, 1183-91 (1909). (20) - AND MENZIES,A. W. C.. "Electrical Conductivity and Viscosity of Concentrated Solutions of Orthophosphoric Acid," ibid.,31, 11914 (1909). (21) "Does Calomel Furnish Another Contradiction of the Theory of Heterogeneous Dissociation Equilibria?' ibid., 32, 187-9 (1910). (22) - AND MeNzr~s,A. W. C., "Studies in Vapor Pressure. I. A Method for Determining under Constant Conditions the Boiling Points of Even Minute Quantities of Liquids and of Non-Fusing Solids," J. Am. Chem. Sot., 32,897-905 (1910).
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A. W. C., Tomrnon Thermometric Errors in the Determination (23) - AND MENZIES, of Boiling Points under Reduced Pressure," ibid., 32,90+7 (1910). (24) -AND MENZIES, A. W. C., ''Studies in Vapor Pressure. 11. A Simple Dynamic Method, Applicable to Both Solids and Liquids, for Determining Vapor Pressure, and Also Boiling Points a t Standard Pressures," ilrid., 32, 907-14 (1910). (25) -AND MENZIES,A. W. C.. "Studies in Vapor Pressure. 111. A StaticMethod for Determining the Vapor Pressure of Solids and Liquids," ibid., 32, 141234 (1910); Ann. Physik., 33, 971-8 (1910). (26) - AND MENZIES,A. W. C., "Studies in Vapor Pressure. IV. A Redeterminaof Mercury from 250 to 435'," J. Am. Chcm. Soc., tion of the Vapor Press32, 1434-7 (1910); Ann. Physik., 33, 97(1910). (27) -~ mMENZIES, , A. W. C., "Studies in Vapor Pressure. V. A Dynamic Method for Measuring Vapor Pressures, with Its Application to Benzene and Ammonium Chloride," J. Am. Chm. Soc., 32, 1448-59 (1910); Ann. Physik., 33, 989-94 (1910). (28) - AND MENZIES,A. W. C., "Studies in Vapor pressure. VI. A Quantitative Study of the Constitution of Calomel Vapor," J. Am. Chem. Soc., 32, 1541-55 (1910). (29) - AND MENZIES,A. W. C., "D~mpfd~uckuntersuchungen.VII. Der Dampfdruck von getrockneten Kalomel," Z. physik. Chem., 76, 715-20 (1911). (30) - AND CARSON,C. M., "Ueber den amorphen Schwefel. VII. Die Gefrierpunktskurven des fliissigen Schwefels bei der Abscheidung von perlmuttartigen. bzw. rhombischem Schwefel," ilrid., 77, 661-76 (1911). (31) - AND MENZIES,A. W. C., "New Hydrate of Orthophosphoric Add," Roy. Soc. Edinburgh, Proc., 3 0 , 6 3 4 (1911). R. P.. "Dissdation Pressures of Ammonium- and Tetra(32) - AND CALVERT, methylammonium Halides and of Phosphonium Iodide and Phosphorus Pentachloride," I. Am. Chem. Soc.. 36, 136342 (1914). R. H., "Densities and D~greesof Dissociation of the Saturated (33) -AND LOMBARD, Vapors of the Ammonium Halides, and the Related Thermal Data." ibid., 37, 38-69 (1915). R. H., "Density and Degree of Dissociation of the Saturated (34) -AND LOMBARD, Vapor of Phosphorus Pentachloride," ;bid., 37, 205W2 (1915). (35) "Die quantitative Zusammensetzung der Dimpfe des Kalomels, der Ammoniahaloide und des Phosphorpentachlorids, aus Messnngeu der Drucke und Dichten ermittelt," Z. Elektrochem., 22, 33-7 (1916). R. P., "Dissociation Pressures of Mernuous chloride." I. (36) - AND CALVERT, Am. Chm. Soc., 38, 801-7 (1916). H. E., "Allotropy and Solubility in Water of Ammonium (37) - AND EASTLACK, Bromide." ihid., 38, 1261-6 (1916). H. E.. "Ammonium Iodide, Its Salnbiities and the Absence (38) - AND EASTLACE, of a Transition Point." ibid., 38, 150fF2 (1916). H. E., AND SCATCHARD, G.. "Transition of Dry Ammonium (39) - AND EASTLACK, Chloride," ihid., 41, 1961-9 (1919).
Bibliography I1 Translator, LASSARCOlIN, "Laboratory Manual of Organic Chemistry," The Macmillan Co.. London, 1896. (2) "Laboratory Outline of General Chemistry," University of Chicago Press. Chicago, 1809; 2nd ed. rev., Chicago, 1902; 3rd ed. rev. with W. J. HALE.The Century Co., New York City, 1907; 4th ed. with W. J. HALE,The Century Co., (1)
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New York City, 1907; 5th ed., "Expperimentental Inorganic Chemistry," The Century Co., New York City, 1917. Translated into German by F. HABEP. AND M. STOCKER, G. Braun'sche Hofbuchdr., Karlnuhe, 1904. Translated also into Spanish, Japanese, Russian, and Italian. --AND HALL.E. H., "Teaching of Chemistry and Physics in Secondary Schools," Longmans, Green & Co., London, 1902. (American teachers' series.) "Introduction t o General Inorganic Chemistry," The Century Co., New York City, 1906; rev. ed., The Century Co.. New York City, 1910; 3rd ed., The Century Ca., New York City, 1917. Translated into German by E. STERN. Karlsruhe, 1909. "Smith's Inorganic Chemistry," revised by J m s KENDALL, The Century Co., New York City, 1926. "General Chemistry for Colleges," The Century Ca., New York City, 1908, rev., The Century Co., New York City, 1916. "Smith's College Chemistry." rev. by J-s KENDALL, The Century Co., New York City, 1923; rev. ed. by JAMESKENDALL, The Century Co., New York City, 1929. "Rehabilitation of the American College and the Place of Chemistry in It," Science, 30, 457-66 (1909). "An Earlv Chemist-M. V. Lomonossov," J. Am. Chem. Sac., 24, . Phvsical . 109-19 (1912); reprinted in Science, 35, 121-9 (1912). Keith Prize and Medal, Roy. Soc. Edinburzh, Proc., 1912, 513. "Textbook of Elementary chemistry," TG Century Co., New York City, 1914. and others, The "Smith's Elementan Chemistry," rev. by JAMES KENDALL Century Co.. New ~ o r City, k 1924. "Training of Chemists," Science, 43, 619-29 (1916); reprinted in J. Ind. Eng. Chm., 8, 52733 (1916). "Laboratory Outline of College Chemistry," The Century Co., New York City. 1916; rev. by JAMES KENDALL. The Century Co.. New York City, 1923; rev. by JAMESKENDALL, The Century Co., New York City. 1929. - A m MOORE,W. C., "Calculations of Inorga@ Chemistry and Qualitative Analysis," The Century Co., New York City, 1918. "Intermediate Textbook of Chemistry," The Century Co., New York City. 1919. L E. E. S ~ o s s o The ~, "Intermediate Chemistry," rev. by J m s K E ~ A LAND Century Co., New York City, 1922. "Laboratory Outline of Elementary Chemistry," The Century Co., New York Citv. JAMES KENDALL and others, The Century > . 1914: rev. and rewritten bv. . Co., New York City, 1924. "Laboratonr Outline of Intermediate Chemistry," The Century Co., New York City, 1919; rev. by JABIES KENDALL, The Century Ca.. New York City, 1922. "Obituary," J n m s KENDALL,J. Am. Chem. Soc., Proc., 44, 113 (1922). "Obituary," A. W. C. MBNZIES,Science, 56, 409 (1922). K E ~ A L LJ a, m s , "General Chemistry, a Cultural Course, Based upon the Texts of the Late Alexander Smith," The Century Co., New York City. 1927.