Intelligence and Miscellaneous Articles, 407 



from Forbes's observations made in 1832 on the Faulhorn and at 

 Brienz*. 



I will further add two results flowing from observations made 

 when the heights of the sun above the horizon were lower. 



With equal atmospheric thickness the radiation at a greater height 

 is undoubtedly stronger than at a lower height. Thus on the 20th 

 of July, at 5.30 p.m., on the Grands Mulets (3000 metres), the atmo- 

 spheric thickness being 1500, the corrected radiation was 15°* 26. 

 Now at Geneva, even under the most favourable circumstances, it 

 scarcely reaches 14°. An observation made in winter on Mont 

 Salem confirms this result, which is also opposed to what Mr. Forbes 

 had found. 



The diminution of the intensity of the radiation with the diminu- 

 tion of the height of the sun above the horizon is considerably less 

 strong at a great height than on the plain ; so that the ratio of the 

 radiation observed at a higher station to that observed at a lower 

 one is greater in the morning and evening than in the middle of the 

 day. — Comptes Rendus, September 23, 1867. 



ON SYSTEM IN MINERALOGICAL NOMENCLATURE. 

 BY J. D. DANA. 



In an interesting paper on the above subject, which appears in 

 Silliman's Journal for September 1867, the author arrives at the fol- 

 lowing conclusions : — 



1. The only chance for uniformity in mineralogical nomenclature 

 is in the general use of the termination ite. 



2. This termination is the best that is available, because of (1) its 

 Original use and signification, (2) its early origin, (3) its almost 

 universal adoption in the science. 



3. If any other termination in addition is to be used, it should be 

 so only under system ; that is, it should be made characteristic of 

 a particular natural group of species, and be invariably employed for 

 the names in that group ; and its use should not be a matter of choice 

 or whim with describers of species. 



As a matter of fact, ine has not been employed for any particular 

 division of minerals, or with reference to any system, and it could 

 not now be so restricted ; and this being the case, it should be put 

 out of the science as far as possible. It belongs by adoption and 

 long usage to chemistry, and should be left to that science. 



tensity of the radiatiou at the limit of the atmosphere. Of course this 

 observation is only offered for what it is worth, and as an indication which 

 may be interesting ; it is in fact clear that, even assuming my observations 

 to be absolutely correct, they by no means suffice to determine with any 

 certainty the form of the curve representing the law of radiation, a law 

 which must be very complex. 



* Phil. Trans, for 1842, part 2, p. 225. 



