134 Afr. Cooper on tt [Feb. 



sulphate by the flux, and would not produce its effect till that 

 salt was decomposed. 



It is very desirable that the presence of potash and soda in 

 minerals could also be discovered by the blowpipe. The pale 

 lilac produced by potash, though it enables a salt of that 

 alkali to be readily distinguished from the salts of soda or 

 lithia, is too faint for affording a test of its presence in mi- 

 nerals, unless it exists in considerable quantity. The pro- 

 perty soda possesses of communicating a yellowish colour, and 

 of making the flame larger at the same time, may be turned 

 to some advantage ; for several minerals that contain soda 

 act on the blowpipe's flame in the same manner as soda itself, 

 from which we may be led to infer the presence of that alkali 

 in them. This has been observed in sodalite, analcime, cha- 

 basie, albite, pitchstone, and several others. Unfortunately, 

 however, a yellowish colour may be produced by other sub- 

 stances besides soda, so that it is a test which cannot altogether 

 be relied on with certainty. Thus, a similar effect is occa- 

 sioned, though in a less degree, by the fluate of lime, and, 

 perhaps, by lime under other circumstances. However this 

 may be, it is certain that many minerals that contain soda give 

 a very distinct yellow colour to flame ; it is a circumstance, 

 therefore, which may be useful to the chemist and mineralogist, 

 and as such I mention it. 



I beg leave to observe, in conclusion, that experiments on 

 the colour communicated to flame should be performed with a 

 tallow candle, the colour of which is better fitted for the pur- 

 pose than that of a spirit-lamp. 



Article XI. 



Description of a new Species of Grosbeak, inhabiting the North- 

 western Territory of the United States. By William Cooper.* 

 The genus Loxia being restricted by the most eminent 

 modern ornithologists to the Crossbills, the remaining species 

 of graniverous birds having a conical, straight, and pointed 

 bill, and which were arranged by Linnseus, and the authors who 

 have followed him, as a species of Loxia, are now all compre- 

 hended under the genus Fringilla. The number of species 

 thus brought together is consequently very great; but they 

 present such a gradual passage from one character to another, 

 that it is found nnpracticable to separate them into well defined 

 and natural genera. In order to avoid, however, the inconve- 

 nience which would result from so many species being compre- 



• From the Annals of the Lycenm of the Natural History of New York. 



