Intelligence and Miscellaneous Articles • 317 



The chemical characters of this mineral also agree entirely with 

 those of melilite, with this only difference, that the presence of iron 

 is less strongly marked ; but it possesses the same degree of fusibi- 

 lity before the blowpipe, the same easy decomposition by cold hy- 

 drochloric acid, and in forming a jelly, and lastly the same consti- 

 tuent principles. 



By analysis M. Damour obtained the following results : — 



Silica 40-69 



Lime 31'81 



Magnesia 5*75 



Potash 0-36 



Soda 4-43 



Alumina 10*88 



Peroxide of iron . . 4*43 

 98-35 

 M. Damour observes, that in this analysis there occurs the same 

 relation as in that of the melilite, between the quantities of the 

 bases and the silica. It is, however, to be observed that the propor- 

 tion of peroxide of iron is much smaller than that of the alumina, 

 and that the reverse occurs in melilite ; but as the isomorphism of 

 peroxide of iron and alumina is well known, they may be substituted 

 for each other without changing the relations between the parts of 

 a compound to which they belong ; many minerals, and especially 

 garnets, offer numerous examples of this fact. 



It is further remarked by M. Damour, that his analysis of this mi- 

 neral agrees almost entirely with that of M. Kobell {Annates des 

 Mines, tome v. 1834), but they differ in one estimating the iron in 

 the state of protoxide, and the other in that of peroxide. M. Da- 

 mour, adopting the latter opinion, considers that the same formula 

 may be given for melilite and humboldtilite, and proposes to reject 

 the former name. — Ann. de Ch. et de Phys., Janvier 1844. 



ANALYSIS OF GUANO. BY MM. J. GIRARDIN AND BIDARD. 



This analysis was undertaken by the desire of the Agricultural 

 Society of Rouen, and the specimen appears to have been furnished 

 by the Society. 



It was mechanically separable into two distinct parts : one of 

 which was a brown moist powder containing a great quantity of car- 

 bonate of ammonia, and the other consisted of small white gravelly 

 pieces, which were somewhat hard, which differed only from the pre- 

 ceding powder in not containing any carbonate of ammonia ; this 

 latter portion was submitted to analysis and was found to contain 

 the following substances : — 



Urate of ammonia. Phosphate of lime. 



Oxalate of ammonia. ... ... magnesia. 



potash. Sulphate of potash, 



lime. Chloride of potassium, ^ very little. 



Phosphate of ammonia. Fatty matter, 

 potash. 



