NA TURE 



.S6i 



gleichzeitigen 

 Herausgegeben 

 Akademie der 

 (Munchen und 



THURSDAY, OCTOBER 12, 1893. 



THE CORRESPONDENCE OF BERZELIUS 

 AND LIEBIG. 



Berzelius und Liebig. Ihre Brlefe von 1831-1845. Mit 

 erlauternden Einschaltungen aus 

 Briefen von Liebig und Wohler. 

 mit Unterstiitzung der kgl. bayer. 

 Wissenschaften von Justus Carriere. 

 Leipzig: J. F. Lehmann, 1893) 



THIS most interesting, and, for the historian of 

 chemistry, most valuable little book owes its origin 

 to a sentiment akin to that which prompted the publication 

 of the no less interesting and valuable collection of the 

 letters of Liebig and Wohler. How important the corre- 

 spondence of Berzelius and Liebig is to him who essays 

 to write the history of the chemistry of the nineteenth 

 century will be obvious from the fact that this exchange 

 of letters occurred during one of the most eventful 

 decades of the century. It began at the period of 

 the epoch-making work of Liebig and Wohler on 

 tlie radicle of benzoic acid, and extended over the 

 time when Liebig was devoting himself, with charac- 

 teristic ardour and enthusiasm, to the study of animal 

 chemistry and to the applications of chemistry to agri- 

 culture. Frequent reference, as might have been 

 expected, is made to these and the many other matters 

 which during that time engaged the energies and occupied 

 the thoughts of Liebig at what was the most active and 

 the most fruitful period of his career. Nor was Berzelius 

 less communicative concerning his own work. Nothing, 

 however, is more characteristic of the difference in tem- 

 perament of the two men than the manner in which each 

 speaks of what he has done, is doing, or means to do. 

 With Berzelius it is nearly always concerning what he 

 has accomplished, seldom of what he is doing, and still 

 more rarely of what he is going to do. The sanguine, 

 ardent character of Liebig is reflected in almost every 

 letter. He is terribly in earnest on the matters of the 

 moment, and full of enthusiasm and confidence concern- 

 ing the plans of the future. The philosophic calm which 

 pervades every letter of the great Swedish chemist is a 

 source of wonder and envy to his correspondent. 



" I envy you," writes Liebig, " the priceless tranquillity 

 of mind with which you do your work. Pray tell me is it 

 always so with you. Has not the keen desire for dis- 

 covery not even once made your heart beat quicker ? 

 With you there is an ever present intellectual calm." 



Liebig wrote as he thought and spoke. " I cannot, 

 like others of cooler blood," he wrote to Wohler, "keep 

 myself apart from and unidentified with my work : what 

 I do I do with all my faults and shortcomings, but also 

 with all the energy that actuates me." 



The letters, therefore, are valuable not only as side- 

 ights on matters which are now regarded as classical 

 in the history of chemistry, but also as evidence of 

 the character and temperament of the two men ; and 

 from this point alone they will have a special interest 

 for the historian of science. 



The correspondence begins with a new year's letter 

 from Liebig in the January of 1831. The two chemists 

 NO. 1250, VOL. 48] 



had made one another's personal acquaintance at Ham- 

 burg during the summer of the preceding year, and 

 Berzelius had already expressed to his friend and former 

 pupil Wohler, the pleasure it had afforded him to meet 

 Liebig. Liebig had perfected his method of organic 

 analysis, and the Giessen laboratory was busily engaged 

 in determining the elementary composition of whole 

 series of organic substances, and he gives in his first letter 

 a brief account of the main results to which he and his 

 pupils had arrived. Berzelius in his acknowledgment 

 congratulates him on his work : — 



" It is quite incomprehensible to me how you can have 

 accomplished so much in so short a time." 



He tells Liebig of the discovery of a new metal by 

 Sefstrom, which the discoverer had named Vanadium : 



" It is an interesting thing. It will take its place be- 

 tween chromium and molybdenum. Wohler had well- 

 nigh lighted upon this body. He undertook to analyse 

 lead chromate from Zimapan. He discovered that the 

 substance hitherto regarded as chromic acid was not so 

 in reality, but gave himself no further trouble to determine 

 what it actually was." 



Wohler has himself told us the story, and let the 

 world see the characteristically humorous letter in which 

 Berzelius " chaffed" him for being too lazy to open the 

 door when the goddess knocked. 



There is the customary Teutonic contempt for most 

 things Gallic : 



" It gives me a real pleasure to read your writings by 

 reason of the love for truth which pervades them — in 

 striking contrast with Dumas, who seems to do every- 

 thing for show." 



In the second letter Berzelius writes :— " Die Uiizu- 

 verlassigkeit der franzosischen Analysen. ... 1st 

 eine verdammt curiose Sache," and again Dumas and 

 his pupils are somewhat severely handled. Berzelius 

 is "so satt" with Vanadium that he is constrained 

 to tell Liebig all he knows about this " sehr in- 

 teressanter Korper." He has just finished his memoir 

 for Poggendorff " in welcher die viele Salzbeschreibungen 

 gewiss manchen Leser einschlafen machen werden." 

 The letter was written with the so-called "vanadium 

 ink," made by adding extract of gall-nuts to a solution of 

 ammonium vanadate. "It flows," says Berzelius, "so 

 extraordinarily well that it is preferable to all iron inks, 

 and fades less easily." Unfortunately Berzelius's ex- 

 pectations respecting the new ink have not been fulfilled : 

 the writing of this particular letter, the editor points out, 

 has become quite yellow, and is difficult to decipher. 

 Liebig does not altogether share Berzelius's opinion 

 respecting Dumas : 



" Small as is the confidence I have in Dumas' work, 

 the calculations of this rope-dancer seldom fail in their 

 object : I have assured myself by a direct determination 

 of the vapour density of the non-inflammable gas [phos- 

 phuretted hydrogen] that he is right. I am continually 

 annoyed that the fellow, in spite of his wretched and 

 slovei.ly style of work, should shake masterpieces, so to 

 say, out of his sleeve." 



In 1831 Liebig's position at Giessen, in spite of his 

 growing fame, was pecuniarily very poor. He writes 

 to Berzelius : — 



" 1 have latterly taken upon my back a big burden in 

 yoking myself with Geiger as co-editor of his magazine, 



B li 



