DEATH OF HACHETTE. 65 



You have probably heard of the death of onr friend M. 1834. 

 Hachette at Paris. It took place in January last, but I did not Letter from 

 learn it till about a fortnight ago, in a letter from M. Quetelet. 

 ... I have met with very few men of science whom I have so 

 much admired and esteemed as M. Hachette. He had an ardour 

 in the pursuit and promotion of science not to be extinguished 

 by the shameful treatment which for years he met with ; and 

 his gentleness, kindness, single-heartedness, and generosity were 

 particularly engaging. . . . 



I quite share your feelings of indignation, not only on 

 account of the shameful treatment experienced by M. Hachette 

 for so many years, but also on account of the chary and meagrely 

 doled out measure of justice he has received since his death. As 

 a man of Science he was truly estimable, and laid Science under 

 many obligations not yet acknowledged ; and as a man among 

 French men of Science his character was altogether unique. I 

 am glad that you so decidedly intend doing him justice. 1 



I am glad to know that you are about a work on the Dif- 

 ferential Calculus upon the principles to which you refer. I 

 have long felt that recourse to algebraical expansions in series, 

 in establishing the principles, is exceedingly illogical, and have 

 therefore long been perplexed to know what book to employ as 

 a text-book. In my own class here I have principally employed 



Francceur in the second vol. of his Mathematiques Pures 



The anomalies which you specify are exceedingly curious, and 

 serve still further to confirm me in my long-cherished persuasion 

 that the fashionable process is hollow and unstable, and referable 

 to no irrefragable principle. I wish you complete success accord- 

 ing to your views of what the logic and metaphysics of first 

 principles require in your important and interesting undertaking. 

 . . . And I am, 



Yours very cordially, 



OLINTHUS GREGORY. 



Early in the year 1836 The Connexion of Number and 

 Magnitude was published. It is an attempt to explain 

 the fifth book of Euclid. In the Preface the author says, 

 6 The subject is one of some real difficulty, arising from the 

 limited character of the symbols of Arithmetic considered 

 &s representatives of ratios, and the consequent iiitroduc- 



1 In the Astronomical Obituary Notices. 

 F 



