NA TURE 



[December 5, 1901 



This crying need of a people was voiced by Pasteur 

 more than thirty years ayo, at a time when great 

 national disasters were sweeping all before them ; a 

 quarter of a century later these words sound a prophetic 

 note of warning to another nation which, with similar 

 arrogance and similar criminal neglect, has made a 

 fetish of political illusions whilst the very foundations 

 upon which the soul of the people depends have been 

 forgotten or deliberately ignored. 



" Is it not deplorable, almost scandalous," exclaims the 

 Minister Duruy, "that the official world should be so 

 indifferent on questions of science ? " Would that England 

 had a minister who, whilst sharing such a conviction, 

 possessed the courage to express it I Pasteur with rare 

 prescience was never weary of insisting upon the im- 

 portance of higher education ; " if that teaching is but 

 for a small number, it is with this small number, this 

 ^lite, that the prosperity, glory and supremacy of a nation 

 rest," and we find him again and again returning to the 

 same theme. 



M. Radot takes us step by step along the victorious 

 path which Pasteur cleared in the conquest of the most 

 difficult scientific problems of the day. Vet he reminds 

 us that those imaginative people 



" who would decorate the early years of Louis Pasteur 

 with wonderful legends would be disappointed ; ... at 

 the Arbois College he belonged merely to the category 

 of good average pupils ... at the examination for the 

 hacculaiin'at is sciences he was only put down as 

 mediocre in chemistry." ' 



But all this was to be changed, and under the inspiring 

 influence of two such teachers as Balard and Dumas 

 he became a student of chemistry second to none in the 

 enthusiasm for his subject. 



His discoveries in crystallography soon won for him a 

 foremost place in the scientific world. In a letter from the 

 great physicist Biot to Pasteur's father we have a charming 

 tribute paid by the aged to the young philosopher. 



"It is the greatest pleasure that I can experience in my 

 old age to see young men of talent working industriously, 

 and trying to ])rogress in a scientific career by means of 

 steady and persevering labour and not by wretched 

 intriguing. That is what has made your son dear to me, 

 and his affection for me adds yet to his other claims and 

 increases that which I feel for him." 



Biot's friendship for Pasteur, which ripened into a 

 fatherly love and pride in his work, only terminated with 

 his death and was one of Pasteur's most valued posses- 

 sions. 



It will be remembered how Mitscherlich had discovered 

 that the two tartaric acids so familiar to chemists, while 

 apparently identical in chemical composition, in chemical 

 properties, in crystalline form and, in fact, in every 

 known detail, behaved differently in solution towards 

 polarised light. This distinguished crystallographer, 

 unable to detect any difference in these two tartrates, 

 asserted that they were identical in every other particular. 

 Pasteur could not accept this conclusion as to the abso- 

 lute identity of these substances in face of the fact of 

 their different behaviour towards polarised light, and 

 determined, if possible, to procure some of the inactive 

 tartaric or racemic acid and submit it to an e.xhaustive 

 examination. But how to procure this racemic acid.' 

 Originally obtained in 1820 by Kestner, at Thaun, 

 NO. 1675, VOL. 65J 



through a mere accident in the manufacture of tartaric 

 acid, it had suddenly ceased to appear in spite of all 

 efforts to obtam it again. Pasteur's emotion was 

 immense on hearing from Mitscherlich that a manu- 

 facturer in Saxony had again produced some racemic 

 acid, and that he believed the tartars employed had 

 originally come from Trieste. " I shall go to Trieste," 

 says Pasteur, in a fever of excitement ; " 1 shall go to the 

 end of the world. I must discover the source of racemic 

 acid, 1 must follow up the tartars to their origin." 



Armed with letters of introduction, he starts off on his 

 voyage of discovery and, writes a contemporary, "never 

 was treasure sought, never adored beauty pursued over 

 hill and vale with greater ardour." 



How he succeeded in obtain'ng specimens and in 

 establishing a minute difference in the crystalline struc- 

 ture of these two acids, overlooked by the renowned and 

 experienced Mitscherlich, and how his fundamental dis- 

 covery of the relationship which exists between crystalline 

 form and optical activity, followed up by a series of 

 masterly investigations, has given birth to that fertile 

 offshoot of chemical science known as stereochemistry! 

 is familiar to all. 



The red ribbon of the Legion of Honour was his 

 country's recognition of these brilliant discoveries m the 

 field of chemical science. In the further prosecution of his 

 investigations, Pasteur discovered that if he allowed one 

 of the salts of racemic acid to ferment, the dextro-tartaric 

 component was alone acted upon, which action in his own 

 words he declares to be "the ferments of that fermentation 

 feeding more easily on the right than the left molecules.'' 

 At this time, when his attention was being arrested by 

 the problems of fermentation in connection with the pro- 

 duction of chemical compounds, he was appointed pro- 

 fessor at Lille. Difficulties encountered by a local manu- 

 facturer in the production of beetroot alcohol induced 

 Pasteur to turn his thoughts more especially to the 

 phenomena of fermentation, and these studies led by a 

 natural sequence to his throwing down the gauntlet to 

 the great Liebig and entering single-handed upon that 

 famous contest with the most brilliant intellects of the 

 day as to the origin of the phenomena of putrefaction 

 and decay. 



The current contempt for Pasteur's conclusions may be 

 realised from the following words amanaling from the 

 most distinguished chemist of the day. In 1845 Liebig 

 wrote : — 



"As to the opinion which explains putrefaction of 

 animal substances by the presence of microscopic 

 animalcukc, it may be compared to that of a child who 

 would explain the rapidity of the Rhine current by 

 attributing it to the violent movement of the numerous 

 mill-wheels of Mayence." 



Pasteur relates how, several years later, he visited 

 Liebig in his laboratory, anxious to induce him to 

 acknowledge the truth of his theories ; he was received 

 with kindly courtesy, but on endeavouring to approach 

 the delicate subject he had so much at heart, Liebig, 

 " without losing his amenity, refused all discussion, 

 alleging indisposition." 



The multiplicity and varied character of Pasteur's re- 

 searches have been well-nigh forgotten by a generation 

 which almost exclusively associates his name with the 



