Notices respecting New Books. 437 



It was examined in a very cursory manner by the late Richard 

 Phillips ; and the portion he examined being found to effervesce 

 with acid and to contain silver, he was led to regard it as a car- 

 bonate, and particularly as it so much resembled the carbonate 

 of silver described by Selb. 



A recent examination of it, however, by Mr. Richard Smith, 

 in the metallurgical laboratory at the Museum of Practical Geo- 

 logy in Jermyn Street, shows it to be a very different compound, 

 and one new to mineralogy ; and there can be no doubt that the 

 carbonic acid which deceived Mr. Phillips was derived from the 

 intermixed carbonates of lime and of copper. 



The analysis of two small portions of the earthy part of the 

 substance separated from the matrix gave the following results 

 per cent. : — 



I. II. 



a. b. 



Silver .... 16-09 17-18 



Antimony . . . 7-82 7*50 7-28 



Sulphur .... 1-41 1-84 



Selenium . . . 2*81 3-58 



Chloride of silver . 1-26 2-67 



Oxide of copper . 10-46 8-61 



Silica .... 45-56 41-81 



Alumina .... 2-06 \ 

 Peroxide of iron . 2-21 J ^■"^' 



Lime 172 2-83 



Carbonic acid . . 2-92 3-04 

 Combined water . 2-31 

 Hygroscopic water . -99 

 9^61 

 The whole of the copper contained in the mineral is dissolved 

 out by acetic acid ; from this we may infer that it is not pi-esent 

 in the form of sulphide or selenide. The acetic acid solution 

 was found to contain lime, but did not give any precipitate with 

 the addition of hydrochloric acid, nitrate of silver, or chloride of 

 barium. 



LXIII. Notices respecting New Books. 



Hdghes's Reading Lessons. First Book. London : Longman, Brown, 

 Green, and Longmans. 1855. 



''PHOSE who are practically engaged in the education of youth 

 ■*- will be best able to api)reciate the value of such reading lessons 

 as Mr. Hughes intends his to be, as well as the difficulties which 



