Tobias Lowitz -Discoverer
of Basic Laboratory Methods HENRY M. LEICESTER
College of Physicians and Surgeons, San Francisco, Calqormia HEMISTS who formulate great generalizations or discover new elements and important compounds are assured of permanent fame in the history of their science. Equally valuable, though not so spectacular, is the work of the men who give us the laboratory techniques without which the more startling discoveries cannot be made. Such workers, though they may attain some recognition during their lifetimes, are usually completely forgotten by later generations of chemists, who use the techniques they have developed as routine procedures and give no thought to the effort and skill required to initiate these methods. One of the outstanding contributors of basic lahoratory techniques was the now almost completely forpotten Tohann Tobias Lowitz, or, as he was known in St. pe&rshurg where he spent most of his life, Tovil Egorovich Lovits. R e c o ~ i z e dwhen alive as a worthy su&essor to ~omonosov-in Russian chemistry, he is now nearly unknown, and the efforts of Walden (12,13) to restore to him some measure of fame are now so difficult to locate that they have failed to accomplish their purpose. Lowitz was born in 1757 in Gottingen, the son of Georg Moritz Lowitz, professor of mathematics in the Universitv. In 1767 his father was called to St. Petersbur^ as ~rofessorand member of the Imperial Academy of Sciences. At this time, the ~ c a d e was i ~ the sole center of scientific research in Russia (3). It had been founded by Peter the Great, and opened after his death in 1725. The orizinal members were all foreianers and the foreign influence continued dominant for many years. Even by 1767, only such exceptional Russians as Lomonosov could hope to he members. The scientists who made up the Academy were active workers, and young Lowitz was thus brought up in a true scientific atmosphere. Among the most important activities of the Academy were the scientific expeditions which i t sent all over Russia to study the nature and resources of the country. When Tobias was about 17, he accompanied his father on one of these expeditious to the shores of the Caspian Sea. At this time a great rebellion under the leadership of the Cossack Pugachev was raging in Southern Russia, and Lowitz and his father were captured by a band of rebels. The father was hanged, but the son succeeded in escaping and returned to St. Petershurg. The shock of this experience was so great that he seldom thereafter left the capital (4). In 1776 he became an apprentice a t the Chief Court Apteka, or Apothecary Shop, and after a period of study in Gottingen, he returned as Assistant in the Apteka.
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These aptekas had preceded the Academy of Science as centers of scientific work in Russia. The first had been founded by an English apothecary, James Frenchman, in 1581, and for 200 years, most of the chemical processes carried on in Russia were under the control of the Court Apothecaries (1). The duties of Lowitz,
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TOBIAS Lomrz
both as Assistant and as Court Apothecary, which he soon became, had thus a long chemical tradition behind them to encourage his natural aptitude for chemical work. In the course of his work, Lowitz was called on to prepare and purify many chemicals, and he was active in chemical work, although a t first he considered himself a pharmacist. His early papers, published a t this time, were signed "Tobias Lowitz, Pharmaceuticus." At about this period he began to give instruction in
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pharmacy and chemistry in the St. Petersburg hospitals. One of his duties at the Apteka was the preparation of large amounts of tartaric acid. He found it very dificult to obtain pure, colorless solutions of this substance. In 1785 (5) he began to seek a method for their purification. The phlogiston theory was then in full command of the thoughts of Russian chemists, and Lowitz, too, believed fully in i*. He reasoned that the brown color of the tartaric acid solutions was due to oily material, rich in phlogiston, and he therefore looked for a substance with a strong affinity for the inflammable principle. I t appeared to him that wood charcoal, since it did not give up phlogiston even when heated in a closed chamber with the highest degree of fire, might attract more phlogiston to itself if it came in contact with a suitable source. Since he assumed that heat liberated the phlogiston-containing impurities from tartaric acid, he added powdered charcoal to the brown solutions, heated, and then filtered them. The color was entirely removed. Thus the 6Ist discovery of the adsorptive power of charcoal and its practical application in the purification of substances was based on an incorrect theory, but once Lowitz had observed the fact, he extended his observations and applied his method in a variety of ways which perfectly illustrate his chemical genius. During all the rest of his active career, he continually returned to this subject, tinding new applications and new methods of use. Moreover, nearly all the rest of his work can be traced in a direct line to this fundamental discovery. Several chemists who attempted to repeat his work used partly burned charcoal which still contained much tarry matter, and they reported that their final products were more impure than those with which they started. Lowitz quickly showed that if wellburned charcoal were used, his claims were fully substantiated. He then applied his method to a great variety of substances, purifying acids, oils, alcoholic beverages, and many other preparations. He recommended purifying sugar syrups with it, and was thus a forerunner of the modern sugar-refining industry, and he noted that when honey was treated with charcoal, i t lost all its characteristic taste, and could be "used for sweetening tea, coffee, punch, etc., without the least difference from sugar. I have recently had the honor of setting such tea sweetened with honey before the Imperial Free Economic Society a t one of its meetings here, with the general approval of all the members" (6). He also tested sea water with charcoal and observed that the bitter taste was not removed. "This means, I believe, that the taste does not come from the earthy tar parts, but from the salts. The bituminous part would certainly be removed by the charcoal, the salts not" (7). He advised rnbbing the teeth and gums with charcoal to whiten and purify them and suggested its medical use internally. He proposed to use it as a hygrometer by heating it, weighing while hot, and allowing it to cool in the air. The gain in weight due to adsorbed moisture could then be deter-
mined. The discovery of the properties of charcoal was put to practical use in the sugar and whiskey industries, and its application to the purification of drinking water was developed. In 1790, Lowitz published a book, "Anzeige Eines Neuen Mittels, Wasser Trinkbar zu Machen" (2). By 1794 the method was being used on a commercial scale in the water works industry and by the Russian Army on the Moldau (8). However, Lowitz did not receive full credit for his discovety, since in the same year the Economic Society awarded a prize to a certain Grachev for a purification process using a mixture of charcoal and ground rice ( 2 ) . Lowitz was made a corresponding member of the Academy of Science in 1787, and an adjunct member in 1790. In 1793 he became a full member and succeeded to the chair of chemistry formerly held by Lomonosov. His second major discovery followed directly from his first. He used charcoal to purify vinegar, and by rectification of the purified product, he obtained nearly pure acetic acid. The great cold of the Russian winter had previously been used by chemists in their studies, notably for freezing mercury, and it is therefore not surprising that Lowitz was able to freeze acetic acid for the first time, and thus to bring about its complete purification. He determined the freezing point as 1 6 O as against the present value of 16.5' and introduced the term "eisessig" for glacial acetic acid. During the work he noticed that a t times the liquid could be cooled to 3' before ~olidificationand rise in temperature took place. This led him to the study of supercooling, not only with pure substances but also in solutions, and he soon discovered the phenomenon of supersaturation in solutions. In 1795 he thus described the effect of inoculating a supersaturated solution with a crystal of the dissolved substance: "When crystallization begins, it always takes place violently. There is a lively inner movement of the solution. The quietneSs which had been necessary up to this point is dispelled, and small crystals move up and down and swing around on all sides so that at the end there are unformed salt lumps instead of regular crystals. In some salts, rays of the salt suddenly coagulate evenly throughout the whole volume" (9). By this work, his attention was drawn to studies of crystallization and crystal form. He discovered the hydrate NaCl.2Ha0 and was the first to crystallize sodium and potassium hydroxides, as well as a large number of salts. He was also the 6Ist to study and identify salts under the microscope. I t was nearly a hundred years before this work was further developed by Behrens ( 2 ) . From these investigations followed his studies on freezing mixtures. By mixing pure sodium or potassium hydroxide with snow he produced temperatures low enough to freeze mercury, and he was the first to recommend the use of calcium chloride in freezing mixtures. His studies with calcium chloride, which he obtained in anhydrous form, led to the preparation of anhydrous
ether and alcohol, which had never before been com- tions of chemistry, and from time to time it will become pletely dried. He gave the first table of the specific 'still more complicated and difficult as we gradually gravity of alcohol as a function of its water content (10). come to know more new individual components of A number of his lesser studies were also offshoots of the minerals. Each newly discovered earth or metal main line of his scientific development. Thus, whiie rapidly gives rise to an increase in the operations needed working with acetic acid he fist prepared trichloro- for the study of other minerals. Since this is immediacetic acid, and his studies with caustic alkalies led to ately accompanied by a greater cost of time, it will the development of a method for decomposing silicates finally happen that, due to his short span of life, with potassium hydroxide solutions. It is interesting one man alone will be able to examine only a few minto observe how all of his important later studies, no erals with the accuracy and patience needed to observe matter how apparently diverse, follow in a direct and them. This evil result must infallibly lead us to fear logical way from his original discovery of adsorption by that an ever-increasing delay in our progress in the study of nature will follow. This undesirable condicharcoal. The work on crystallization of salts aroused in him a tion could easily be prevented if more chemists would great interest in natural minerals, and their composi- act in their work for the good of their profession, for tion. He worked with both strontium and chromium, the surely important object of easing and shortening but was anticipated by Klaproth and Vauquelin before operations, and finding new, or a t least, useful methods he could announce his discovery, so that he was un- for separations, or finding methods of investigation, able to claim the discovery of a new element. His things which they now seem to regard as trivial, and at active career came to an end as a result of his work on once making these known and generally useful in some chromium, for in 1800, whiie studying this metal, he chemical journal. . ." (11). lost his left hand as the result of a laboratory accident REFERENCES 1 A long iUness followed, and he never completed Lancef, 1897,U, 343-74. any further important work. - ~died e in St. ~ e t k s b u r ~(1) ANONYMOUS, M.A,. "Chronolom of the Most Imnortant Events (2) . law. , BLOKH. m in the ~ i e l dof ~herni&y." State Scientific-Technical The scientific activities of Lowitz are not only an Press. Leningrad and Moscow, 1940,pp. 78.82. (3) BRASCH, F.E., Science, 99,437-41 (1944). example of a brilliant and an active mind, which was (4) K u z ~ ~ ~ sB. o vG., , "Sketches in the History of Russian able to see applications of a most varied character Science." Academy of Science of the U. S. S. R., Moscaw and Leningrad;1940, p. 70. stemming from one fundamental piece of work, but Lowrrz, T., Crell's Chern. Ann., 1786,I,293-300. they are also amazing for the number of basic laboratory Lowr~z,T., ibid., 1788, If, 3641. techniques which they have given us. Lowitz himLowr~z,T., ibid., 1791,I, 308-24. Lowrrz, T.. ibid., 1794,U, 514-15. self was not unaware of the importance of methods LOWITZ, T., ibid., 1795,I, 3-11. which are usually taken for granted by chemists. The Lowr~z,T., ibid., 1796,I,195204. spirit of his words, written in 1799, can still be applied LOWITZ, T., ibid., 1799,II,283-90. WALDEN, P.,in DIERGART, P., "Beitrsge aus dem Geschichte today: "Chemists should help to make operations der Chemie dem Gedachtnis von Georg W. A. Kahlhaum." easy. The decomposition of mineral bodies is unquesDeuticke, Leipzig and Vienna. 1909,pp. 53344. WALDEN, P., Chem.Ztg.. 39,3734(1931). tionably one of the most difficult and toilsome opera~
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