EDITOR'S PREFACE 



FOR some time past I have been engaged on the bio- 

 graphy of Christian Friedrich Schonbein, the discoverer 

 of ozone and the inventor of guncotton, formerly professor 

 of chemistry and physics at the University of Bale, the 

 hundredth anniversary of whose birth will be celebrated 

 on the 18th of October of next year. Schonbein's family 

 have assisted me in the kindest manner in this work; 

 they have placed at my disposal the whole mass of papers 

 which this indefatigable physical chemist left behind, 

 and the many hundreds of letters which he received. 



Such writings, far more than the sifted published 

 results, give us a true insight into the thoughts of the 

 writer, and enable us to understand the workings of his 

 mind. We have, moreover, a never-failing series of 

 incidental allusions to the conditions, the manner and 

 the difficulties of sending letters, the calculation of the 

 cost of postage, and the time taken in travelling ; and 

 thus there develops almost insensibly before our eyes a 

 picture of a bygone age, which forms a background to 

 the image of the writer himself. We are continually 

 meeting with casual remarks, begotten of the confidence 

 of the moment, which reveal to us ever new traits of 

 character, and seem to bring the writer before us in person, 

 and to turn into tangible figures those who before were 

 to us often only names and shadows. 



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