November 4, 1920] 



NATURE 



303 



The History of a Mind. 



Pasteur: The History of a Mind. By Prof. Emile 

 Duclaux. Translated by Erwin F. Smith and 

 Florence Hedges. Pp. xxxii + 363. (Philadel- 

 phia and London : W. B. Saunders Company, 

 1920.) Price 215. net. 



PASTEUR has been fortunate in his bio- 

 graphers. There is the well-known life by 

 Rend Vallery-Radot, which describes for us the 

 man himself, his noble, impulsive character, his 

 thirst for knowledge and zeal for humanity, and 

 gives a general account of his researches and dis- 

 coveries; an essay by Sir George Newman, which 

 appeared some twenty years ago and deserves re- 

 publication, expresses in eloquent terms an appre- 

 ciation of Pasteur's life-work from the English 

 point of view ; while, for the purpose of scrutiny 

 of the details of the discoveries themselves, we 

 possess studies by two of the master's disciples, 

 Duclaux and Roux. The volume now under review 

 is a translation by two American pathologists of 

 Emile Duclaux's "Histoire d'un 'Esprit." In 

 French it is the volume which every serious 

 student of Pasteur's work has read, and it is a 

 little surprising to find, not only that twenty-four 

 years have apparently elapsed before the appear- 

 ance of an English translation, but also that the 

 original work appears to be almost unknown out- 

 side France, according to the senior translator. 



The introduction to the book takes mainly the 

 form of a brief memoir of the author. As Boswcll 

 derives his fame from Dr. Johnson, and Lockhart 

 is known as the biographer of Scott, so Duclaux 

 will live chiefly in the shadow of Pasteur and by 

 this book. As a chemist, he was first closely 

 associated with Pasteur in 1862 at the Ecole 

 Normale; separated from him for a short time on 

 becoming professor of chemistry at Tours, he was 

 soon transferred to Clermont-Ferrand, where a 

 portion of his time could be given to Pasteur's 

 work ; subsequently he went to Lyons as professor 

 of physics for five years, and in 1878 he came to 

 Paris as professor of meteorology in the Agro- 

 nomic Institute. In 1888, when the Pasteur Institute 

 was founded, Duclaux joined the stafF assembled 

 under the command of Pasteur, numbering such 

 illustrious names as Chamberland, Roux, Nocard, 

 Granchcr, MctchnikofF, and Yersen among his 

 colleagues. Duclaux's function was the intelli- 

 gence department, the dissemination of discoveries 

 to th«' world— not the actual research work. He 

 r<>iiiuled I^s Annates de I'lnslitut I'asteur, and in 

 iloing created the channel through which the 

 wealth of the discoveries made by Pasteur and his 

 to workers poured to the open sea of scientific 

 NO. 2662, VOL. 106] 



knowledge. Duclaux was an organiser. He 

 wrote well, with all the vivacity and picturesque 

 style of which a master of the French language 

 is capable ; there is not a dull page in his scientific 

 treatises. He found his mitier as an editor and 

 an interpreter of the labours of others. An ardent 

 toiler, who early adopted Pasteur's motto, " il faut 

 travailler toujours," Duclaux himself did little 

 original work. His books, " Ferments et 

 Maladies" (1882) and " Le Microbe et la 

 Maladie" (1885) were records of Pasteur's 

 labours ; he collated and co-ordinated the scattered 

 facts on enzymes, classed them into groups ac- 

 cording to their reactions, and proposed a scheme 

 of terminology for them. In a word, he was one 

 of the earliest administrators in science. On the 

 death of Pasteur, in 1895, he succeeded him as 

 director of the Institute, and died himself in 1904. 

 In the book before us, Duclaux traces in detail 

 the steps by which Pasteur was led to make his 

 famous discoveries. "Que pent bien etre I'hixtoire 

 d'un esprit?" is the first sentence of the original 

 work, and then the author proceeds to show how, 

 in the hands of Duclaux, the task is possible. 

 Guided by him, we follow Pasteur through the 

 thicket of truth and error. We observe how, 

 amid the storm of criticism and controversy, 

 Pasteur advanced unshaken, and if ever he missed 

 his way for a moment, as in the earlier days of 

 the conflict on spontaneous generation, how 

 speedily and surely he retraced his steps. Duclaux 

 tells us the fascinating story of the first work on 

 crystallography, when the foundations of stereo-, 

 chemistry were well and truly laid. As a chemist, 

 Duclaux lingers over this early work ; we can 

 readily understand how great a pure chemist was 

 lost in Pasteur when he chose to become the first 

 bacteriologist. Yet, as Duclaux reveals to us. all' 

 Pasteur's life-work pursued an orderly sequence : 

 the study of crystals led to the researches on 

 ferments. " If one of the salts of racemic acid, 

 paratartrate or acetate of ammonia, for instance, 

 is placed in the ordinary conditions of fermenta- 

 tion, the dextro-tartaric acid remains in the liquor, 

 the rea.son being that the ferment of that fer- 

 mentation feeds more easily on the right than on 

 the left molecules." Pasteur found then that 

 molecular dissymmetry appeared as a modifying 

 agent on chemical affinities in a physiolof^ical 

 phenomenon, and it was a mere step for his ■ 

 mighty intellect to proceed to solve the problems 

 of lactic and alcoholic fermentations, of sponta- 

 neous generations, and of the diseases of wines 

 and silkworms. Short, too, was the step again 

 for Pasteur from these studies towards the 

 etiology of microbial diseases, the wonderful work 



