264 



NATURE 



[August 24, 191 1 



family feature, reappear in the faces of some of his children. 

 Ardent, eager, enthusiastic in the pursuit of experiment, 

 his remarkable power of exact observation stood him in 

 good stead. Kindly and tender with children, there were 

 times when eagerness in research or controversy led to 

 exhibitions of impatience, but the steadfast character of the 

 man is illustrated by the persistence of his lifelong intimacy 

 with Friedrich Wohler. This intimacy resulted in a cor- 

 respondence which extended over more than forty years, 

 and had consequences in the lives of both men', which 

 were full of importance for the progress of chemical science. 

 To this reference must be made further on. 



We may now endeavour to sketch, in outline, the state 

 of knowledge and theory when Liebig entered on his career. 

 The modern use of the term element, which had been intro- 

 duced by Robert Boyle in the seventeenth century, was by 

 this time universally adopted, and to the metals on the 

 list had been added such important substances as oxvgen, 

 hydrogen, nitrogen, and chlorine. To use the words of 

 Davy, in one of his researches on chlorine, "Neither 

 oxygen, chlorine nor fluorine are asserted to be elements : 

 it is only asserted that they have not been decomposed." 

 And that is the sense in which the term has, m modern 

 times, always been used. The process of burning or com- 

 bustion was, of course, now always explained by Lavoisier's 

 doctrine, according to which a body in burning combines 

 with the oxygen of the air, and forms one or more chemical 

 compounds with it. At the time that Liebig went to 

 Giessen, in 1S24, Sir Humphry Davy was si ill living, but 

 his scientific career was practically closed, and Berzelius 

 was the predominant authority in matters of theory. Gay- 

 Lussac, in Paris, had made important discoveries relating 

 to the proportions in which gases enter into combination. 

 Dalton's atomic theory, propounded in 1808, though not 

 generally accepted, was gaining ground. Broadly, the 

 position was (his : elements were clearly distinguished from 

 compounds, chemical combination was explained by the 

 supposition that it was due in the close approximation of 

 atoms of opposite kinds, and the union of atoms to form a 

 chemical compound was attributed to the attraction caused 

 by charges of electricity of opposite nalure, which were 

 supposed to be resident on the atoms. 



But the composition and nature of "organic" compounds 

 were practically unknown. A few such substances had been 

 isolated, e.g. milk sugar and grape sugar were known as 

 distinct substances, and were differentiated from common 

 sugar. Alcohol, nearly pure, had been known, in the form 

 of spirit of wine, from early times. Acetic acid was 

 known, as well as several acids found in vegetable tissues, 

 such as oxalic, formic, malic, tartaric, and benzoic acids. 

 There were, however, no means of determining their com- 

 nosition, and although Lavoisier had devised an apparatus 

 in which organic compounds could be burned in oxygen, 

 and the water and carbon dioxide thus formed could be col- 

 lected, the process \\.i- both cumbrous and incapable of 

 yielding exact results. 



A most interesting autobiographical sketch was dis- 

 overed among Liebig's papers many years after his death, 

 and from this we learn that in his early life " at most of 

 the universities there was no special chair for chemistry, 

 ft was generally handed over to the professor of medii ine, 

 who taught as much as he knew of it, and that was little 

 enough, along with toxicology, materia medica, &c." 

 But the total neglect of experiment was the source of 

 much mischief, and the persistence of the degenerate 

 deductive method led to neglect of the careful observation 

 of nature. The lectures of Prof. Kastner Liebig describes 

 as without order, illogical, and they resembled the jumble 

 of knowledge which he carried about in his own head. 

 When he got to Paris all was different, and the lectures 

 of Gay-Lussac, Th^nard, and Dulong had for the youns 

 student an indescribable charm. The- lecture consisted of 

 a judicious series of demonstrations experiments of which 

 the connection with each other was pointed out anil ex- 

 plained; and soon the consciousness dawned on him thaf 

 all chemical phenomena, whether exhibited by the animal, 

 .il kingdoms, are connected togethei by 

 ~:\fd laws. 



Liebig then fore returned from Paris to his own country 



with ill" intention of founding an institution in which 



students could be instructed in the arl and practice f 



chemistry, the use of apparatus, and the methods of 



NO. 2l82, VOL. 87] 



chemical analysis. In view of the total absence of such 

 provision elsewhere, it is not surprising to learn that, so 

 soon as its existence became known, students streamed 

 into the Giessen laboratory from every civilised country. 

 It is interesting to learn from Liebig's own words what 

 was the method he adopted. Obviously, in order to teach 

 a large number at one time, it is necessary to have a 

 systematic plan, and in his case this had first to be thought 

 out and then put to the proof, as no course existed which 

 could be used as a model. He says, however, that " actual 

 teaching in the laboratory, of which practised assistants 

 took charge, was only for the beginners ; the progress of 

 my special students depended on themselves. I gave the 

 task and supervised its carrying out. There was no actual 

 instruction. Every morning I received from each individual 

 a report on what he had done the previous day, as well as 

 his views about what he was engaged on. I approved or 

 criticised. Everyone was obliged to follow his own course. 

 In the association and constant intercourse with each other, 

 and by each participating in the work of all, everyone 

 learned from the others. Twice a week in winter I gave 

 a sort of review of the more important questions of the 

 day. We worked from break of day till nightfall. Dis- 

 sipation and amusements were not to be had at Giessen. 

 The only complaint which was continually repeated was 

 that of the attendant, who could not get the workers out 

 of the laboratory in the evening when he wanted to 

 clean it." 



Such was the spirit and such the method by which a 

 great school was created ! Nor was this the only result. 

 To the influence and example of the school at Giessen may 

 be attributed the rapid spread of the new method of teach- 

 ing chemistry. In 1824 there were no laboratories devoted 

 to the purposes of instruction. A few of the most eminent 

 professors of chemistry — Berzelius in Stockholm, Gay- 

 Lussac in Paris, for example — admitted one or two 

 students already advanced in the subject to practise in 

 their private laboratories, but only as a great favour. In 

 this way Mitscherlich, Rose, Wohler. and Magnus had 

 repaired to Berzelius in Stockholm as Liebig had gone to 

 Paris. But in a few years the fame of what Liebig was 

 doing in Giessen penetrated to other rountries 'if Eu 

 and many of the men who had studied under his direction 

 became teachers in other lands. Here in England no 

 chemical laboratory for general instruction existed, and 

 only in the medical schools were a few tests described and 

 shown. In London the Society "I Apothecaries had a 

 laboratory which had existed since 1671 ; but this was not 

 used for teaching, but as a place of manufacture of drugs 

 for use in medicine. At Cambridge the professor of , 

 istry was a country clergyman, who came up once a year 

 to give a course of lectures. At Oxford the professe 

 chemistry was also, later, professor of botany, and in 

 neither university was there a laboratory for instruction, 

 nor was chemistry a subject recognised in the curriculum 

 for a degree. Twenty years later things hegan to improve. 

 In this country the first laboratory for instruction in prac- 

 tical chemistry was provided by the then newly instituted 

 Pharmaceutical Society of Great Britain at their pre; 

 in Bloomsbury Square. This was in 1S44. and in the 

 following year a new and enlarged laboratory was fitted 

 with places for twenty-one students.' About this time 

 the College of Chemistry was established in temporary 

 quarters in George Street, Hanover Square, and soon 

 afterwards the- Birkbeck Laboratory, modelled on that of 

 the Pharmaceutical Society, was built at University 

 College Manv other laboratories were opened about this 

 linn-. In 1848 r.le.11.-. founded in Paris a laboratory to 

 which some English chemists resorted. But the Giessen 

 laboraton undei I iebig's direction continued to supply the 

 majority of the te achers who in the- succeeding generation 

 founded schools, not only in Germany, hut in other 

 countries — Hofmann, feir example, at the Royal College of 

 Chemistry, and Williamson, who was appointed at 

 University College in 1840. 



Liebig's career as a chemist and investigator wi 

 fluenced in ne> small degree by his friendship with 

 Wohler. Born tin--- rears before 1 iebig, Friedrich Wohler 



1 [__ saw this laboratory about 1657. It had the aspect which ones usually 

 associates with ideas of the alchemists. Manv of the e>perations were con- 

 nected with the use of furnaces, such as fusion, sublimation, &c.,and the 

 place was full of smoke and fumes. 



