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SCIENCE UP TO DATE, Issue 15696, 9 January 1915
SCIENCE UP TO DATE
[By Jambs Collesb.]
[Special Bights Secured by the ' Star.']
A CONSTRUCTIVE CHEMIST.
Almost seventy years ago two ardent young men resided in a scholastic boardinghouse at Paris that acted a* a feeder to Henry the Fourth's Lyceum, a distinguished college where the elder acted as usher or coach, and the younger was still a pupil. The first was Ernest Renan, who had just left Saint-Sulpice. the training Bchool for French priests; the second,four years younger, was Mareellin Berfheloi. Though their purs-uts varied, there was ,1 singular parallelism in their lives. They were lifelong and bosom friends. Eacn pa.ssed from obscurity tiy worldwide celebrity. Both became professors at the College de France. Both entered the. French .Academy. Both abandoned the Catholicism in which they had been reared. Yet both were publicly feted in their lives and honored in their graves. Both aimed at a. public career, and ones of them became Foreign Minister of France. It is this Litter whose scientific discoveries we shall to-dav rehearse. Marcellini Berthelof was born "in 1827 at Paris where Ms father was .1 successful mp.dii-:il practitioner. As stated, he was educated at the Lycee Henri IV. Doubtless influenced by Kenan, ho inclined to give himself up to the tdudy of philosophv, but, perhaps move powerfully influenced by his father, he devoted himself to tho pursuit of physical science, and especially of chemistry. He. was appointed demonstrator to the veteran Balard. Here began his great career. By a stroke of luck'or by the'instinct of genius, Ber'thelot fastened on that branch of chemistry where fame was to be won. Leaving inorganic chemistry wholly on one side, he devoted hfrnsodf exclusively to organic chemistry. It is by far the more difficult of the two divisions. Mineral compounds are easy to break up and easy to put together "again. It is otherwise with the products of tho living world. Even the simpler of these—such as sugar, starch, butter, and oils—are hard to take to pieces. To tliir. day certain of tho more complex, such as the ferments and the protoplasms, have been hut approximately analysed. So much, however, is known: the "entire organic kingdom virtually consists of only four substances—water, oxygen, hydrogen, and nitrogen. These, with carbon as their base, make up the realm of life in its widest sense. All tho myriad varieties that it unfolds are resolvable into combinations of these. More still we can affirm. An incredible number of substances though two are just as astonishing as 200—are made up, not only of the same four elements, but of the?© in identical proportions. —Vital Forces. —
now explain this strange anomaly? It is the work of the " vital forces." So eaid the greatest chemists of the day—Berzelius, the Swedish ruler of the. science during the first half of the nineteenth century, and Gerhardt, the French reformer of it. Both of these eminent chemists declared that man could do nothing but analyse the substances that ho found. He tears them in piecee, burns, and destroys : he cainot put them together again or build up. Even if he could produce them out of inorganic elements, it would be only an imitation, never a reality. Nature alone, with her .vital forces, can effect their synthesis. Yet at least tiro organic bodies had been already produced by the combination of inorganic elements. A quarter of a ccnturv before ik-rthelot began his experiments Woehler had manufactured urea by artificial acencr. Another German chemist, Kolbe, "produced the acid of vinegar 111 1845 -Vnd Liebig, Woehler's collaborator, realised" that these advances heralded'the dawn of a now science. Do we woncier that the Germans aim at the conquest of tho world when they have done so much to conquer Nature? Or, rather, do not their patience and tenacity teach us a leeson?
—Fraeternal Substances. —
The German Emperor calls France moribund; it was France that now camo to the rescue. In his early manhood P.ertholot picked up tho dropped stitch of 'the German chemists and began where they left off. In five years, it has been scid, he created a new science—synthetic chemistry. , Feeling his way he first analysed glycerine, and. then "out of its elements he built up new- combinations. Almost unawares bo had struck a rich lode, and nugget after nugget rewarded the diggers efforts. He analysed alcohol, and soon learnt to make it for himself, lie. distilled the malodorous ant, and with the gas ethylene he manufactured formic acid. He. attacked the fats and the sugars and found them the most fruitful of all the organic substances. All this was the work of five rears. Ho next effected the synthesis of ' acetylene, now universally known as a useful and .sometimes dangerous illuminant. It was only a beginning. Acetylene condensed by heating was converted" into_benzine, and benzine in the hands of German chemists was made the base of innumerable compounds. Let hydrogen be, added and benzine becomes "ethylene. Let ethylene be_ mixed with water and the alcohol of spirituous liquors is yielded. By this wonderful succession of discoveries Berthelot revealed a new world. He banished the "vital forces" of the'elder chemists, and showed man to be "more, powerful, varied, and ingenious than nature, itself." For ho not only remade the compounds he dissolved; he'also fabricated compound substances such as Nature never knew. The number of artificial compounds known in the laboratory exceeds 50,000. Even this multitude is insignificant when compared with the myriads that could lie manufactured. Tho" 15 or 20 varieties of the fats alone could be multiplied into millions. And tho chief properties of these could be predicted in advance. —'Rewards and Results. — Such was the outcome of little more than 10 vears of persevering experimentation, and in 1860 Berthelot was aide to publish one of the. most scientific treatises of bis time —' Organic Chemistry Founded on Synthesis.' He was only 33 years old. The year before lie had hero appointed Professor of Chemistry at the College of Pharmacy. Next year 1c received the .locker prize. At 38 he was given the first professorship of omanm chemistrv that had been set-up in France at the College de. France, and it. was created for him. He. held it nlmnM. to the last. Berthelot's discoveries initiated vast and lucrative new industries. But it was not he fas ]\fr Karl Snyder appears to imply) who discovered the artificial substitute t>,r maddcr and the indigo that have brought wealth to Germany. These inventions were both ni' German origin. From ingenious and indefatigable German lnboritorios have come the many other dyes. the anaesthetics, and the perfumes already described in these columns. They began in England, and are now. it seems, with tim financial aid of the British Government to be brought back to the emintry of the first invention of at least one of them. The hopeful experiment will i"st the capacity of British chemists and the industry of their workmen. —A Chemometer.— In 1864 Berthelot entered upon a fresh research. Was there any chemical instrument that resembled the electroscope, the galvanometer, and the photometer in furnishing a measure of chemical reactions such as these, other meters afforded of light, galvanism, and electricity? There was none. Where, could one be found : A number of chemists had already engaged in tho research that led to its invention. The key to it lay in, the relations between heat- and chemical action. The Dane Thnmsen, the Irish chemist Andrews, the French Faure. the German Sjlbermann, and the Russian Hess—so many countries now contribute to a, discovery —had pioneered the way. But Berthelot was the final discoverer. He found thatwnen (to takna single example) oxvgen and hydrogen were exploded to" form water, heat is generated. But the amount of the heat can be. measured. A calorimeter was wanted. Berthelot devised on*. His- cMlomefcric bomb fulfilled the conditions. Using it- incessantly, be mado many discoveries, and founded a new hraneh of chemistry-- -thei-mo-chemistry. He had been 15 years at-work on the sub-
ject, when in 1879 he. published his 'Chemical Mechanics, Founded on Thermochemistry,' in two massive volumes. Some 20 yecxs latnr lis completed his researches and published two more volumes. —His Laws.— Be.rthelcs's thrr? _ !vvs of thermochemistry csn he concisely stated, tl) Tho amount of h*at evolved measures the work done, or the force el the chemical iifiinities involved. The .principle, it should be added, is avill in doubt. It electricity plays a, largo -pan, in chemical lcactions, and if chemical aihiiity in nothing els-a than electrical attraction, the- ground v;ill bs cut from under Bcrilwjlot's first law. (2i The second law was iirst enunciated by •Hermann He.ss, ami only accepted by Berihelot, who applied and demonstrated it. Tho .imoiint of lie-at- generated in .1 given reaction depends on the final state reached, however many intermediate stages there may hav* been. (3) " Every chemical change, wnds towards, the production of such compounds as evolve the most heat." That is tbe> most important law of the three, and it is still isder discussion. It explains many tiffinitiuJ, but docs not account for others. It wmld be interesting to follow Bert helots explanation of allotypic forms, Starch and cotton, 'fruit sugar, and tho acid tiiat turns milk sour, red phosphorus and white phosphorus ara examples of these chemical puzzles. They have the .same atoms, and are The samo c-leibcmts, yet they act very differently. "Mow heal" is Berthed ot's explanation. —Theory of Explosives.—
These experiments on iho relation between chemical action and boat led Berth<--lof to his remarkable work on explosives. Here the chemist showed great courage in seeking to measure th-e rate of explosions and determine, the waves of which ho found them to constt. He substituted exact scientific, ideas for the old, vaguo notions, and lie hist predicted, and then manufactured, explosives of far greater fore© than had yet existed. Our Archi-nicdes-Bcrthelot took an active part in the defence of Pari* in 1870-71 Jjc devised new means of resistance. He invented now ammunition. Ho founded cainon and contrived mints. He even, it is said, directed the artillery fire from one. of the forts. For many yearn a fterwards ho was tho permanent head of a commission on explosives, whose ideas are. doubtless embodied in the very superior French artillery fire, now working such havoc or. tha battlefields of Xorlhein Fr;i.nce. c And his collaborator in tho.se experiments, Veille, early invented smokeless powder. -*-Agricultural! Auxiliarics.
In quit* another field Berthelot was to acquire fresh laurels. He purchased a small plot of ground outside of Paris in order to make experiments in aid of agrienltuiv. Ther:' he. had a laboratory of vegetal chemistry. There. 1)6 ascertained that, the. inert nitrogen of the air contributes nothing to tho nutrition of plants. But there, he was to make that ta-mc inactive atmospheric ©lenient- contributa much. A succession of refined experiments showed that the reception of nitrates from the soil—and they ate this plant's chief ftod —was due to the presence of microbe*. "The soil (he expressively said) is in soma sense living." And his experiments, ivoare told, kd to the establishment/ of microbi cultures for the. breeding and sale of germs that enrich the soil. Great advances ha,v« been made in scientific agriculture on thcsij lined in recent years, and some of them have been described in these columns hy the present writer. it will be news tomany readers that Berthelot was the initiator of modes of treating the soil that promise to double or quadruple* its value. His researches led him further He revived an old experiment of Cavendish's, and showed that by means of a high-ten* sion current of electricity the nitrogen oi the atmosphere may be made to combine with oxygen in large quantities. Then lightning rods, leading to large metal plates buried in the ground. much increase the yield of a. field by the nitrogens thus attracted., and used directly as a f eriiliser. This electrical process of manufacturing nitrates has been patented fnnt, by Berfhelot. who never took out a patent), but by commercial companies.
SCIENCE UP TO DATE, Issue 15696, 9 January 1915
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