8 LIGHT SCIENCE FOR LEISURE HOURS. 



Heavens the boldest attempt ever made, perhaps, in 

 this direction not only is precision of expression not 

 a notable feature, but, on the contrary, the most strik- 

 ing fault in the work is the inexactness of the language. 

 Even Sir John Herschel, whose perfect familiarity with 

 the subject of the work would tend to render the fault 

 less obvious to him, was nevertheless truck by it : 

 'The most considerable fault we have to find,' he 

 wrote, ' with the work before us consists in an habitual 

 laxity of language, evidently originating in so complete 

 a familiarity with the quantities concerned as to induce 

 a disregard of the words by which they are designated, 

 but which, to any one less intimately conversant with 

 the actual analytical operations than its author, must 

 infallibly become a source of serious errors, and which, 

 at all events, renders it necessary for the reader to be 

 constantly on his guard.' 



These words form the penultimate sentence of Sir 

 John Herschel's critique. I have preferred to speak 

 first of the subject touched on, so as to pass without 

 reservation to a more pleasing topic the real and 

 unquestionable value of Mrs. Somerville's chief work. 

 And, after all, the good qualities of the work are intrin- 

 sic, while its main fault relates to a purpose which the 

 work never could have fulfilled, no matter how care- 

 fully the fault had been avoided. 



It is in this sense regarding the work apart from 

 its special purpose, and judging of it only as a contri- 

 bution to advanced scientific literature that we may 

 fairly say, with Sir John Herschel, that the work is 



