. 226. THEORY OF THE SYSTEM. 335 



eies occupy the same place in the series. The Croupes 

 of species thus formed are the natural-historical genera 

 (. 225.). In the real existence of genera in the Mineral 

 Kingdom, we discover the reason why there is no series of 

 single species. A more evident demonstration of the pre- 

 ceding observations may be acquired by considering a few 

 examples, for instance, the genera Schiller-spar, Disthene- 

 spar, Triphane-spar, Dystome-spar, Kouphone-spar, Peta- 

 line-spar, Feld-spar, Augite-spar, &c., or the genera of the 

 order Bary te, or of any other somewhat more comprehen- 

 sive order of the natural-historical system of Mineralogy. 

 The series thus representing the Mineral Kingdom is a se- 

 ries of genera, exactly as in the Animal and Vegetable 

 Kingdoms ; and like these it does not contain a series of 

 single species. 



The Mineral Kingdom is constituted by a series of natu- 

 ral-historical genera, each of which contains similar species 

 (if it contain more than one); every one of these, again, 

 being the assemblage of homogeneous individuals. Thus 

 the idea of the Mineral Kingdom receives its fullest evi- 

 dence, and requires in this respect no other notions inter- 

 mediate between that of the genus and that of the Mineral 

 Kingdom. 



The idea of a series requires a beginning and a termi- 

 nal point. There can be no objection to the received or- 

 der of the three kingdoms, in which the Animal King- 

 dom is followed by the Vegetable one, and this again by 

 the Mineral Kingdom ; and it deserves, in fact, that gene- 

 ral reception which it has always found. Those produc- 

 tions of the Mineral Kingdom, which resemble most some 

 of the Vegetable Kingdom, immediately will follow these, 

 and form one of the terminal points in the series of genera 

 which constitutes the Mineral Kingdom. Thus, always 

 according to the principle of similarity, we obtain the whole 

 series of genera, as it is contained in the natural-historical 

 system of the present work. 



It will be useful to add here a few remarks on the recep- 

 tion of what has been called the Atmosphcrilia into the Mine- 



