Notices respecting New Books, . 391 



it is Nature which resumes her rights, and puts a limit 

 to a race of monsters. 



The other circumstance which gave birth to the brilliant 

 idea of passage, is that which takes place when a mineral 

 is an aggregate of two simple species: such are the helio- 

 trope, composed of quartz and green earth; and prase, com- 

 posed of quartz and green schorl (rayonnante) [actinolite of 

 Kirwan and Jameson ; amphibole"* actinote of Haiiy and 

 Brogniart], It is at first a veiy great and irreparable error 

 to consider mixtures as species, the essence of which is 

 simplicity. 



fTo be continued.] 



LXXI. Notices respecting New Books, 



X he Philosophical Transactions for the Year 1810, Part 1 1, 

 has just made its appearance. Its contents^ are: — Sup- 

 plement to the First and Second Part of the Paper of Ex- 

 periments for investigating the Cause of Coloured Con- 

 centric Rings between Object Glasses, and other Appearances 

 of a similar Nature. By William Herschel,LL.D. F.R.S. — 

 On the Parts of Trees primarily impaired by Age. In a 

 Letter from T. A. Knight, Esq. F.R.S. to the Rt. Hon. Sir 

 Joseph Banks, Bart. K.B. P.R.S. — On the Gizzards of 

 Grazing Birds. By Everard Home, Esq. F.R.S. — Obser- 

 vations on atmospherical Refraction as it affects astrono- 

 mical Observations ; in a Letter from S. Groombridge, Esq. 

 to the Rev. Nevil Maskelyne, D.D. F.R.S. Astronomer 



* The union of amphibole (hornblende) with actinote (actynolite) is 

 another fact highly honourable to the study of crystallography. Haiiy an- 

 nounced his opinion of their identity, which was fully confirmed by M. 

 Laugier's analysis in the An. d'Hist. Xal. vol. v. p. 73. 



Amphibole contains Actinote 



Silica 4202 50-OQ 



Oxide of iron 22-69 II <X> 



Magnesia 1O90 19-25 



Lime 9 80 975 



Alumina 7-69 0-75 



Oxide of manganese 115 0-50 



Chromium 000 3-00 



Potash 0O0 0-5O 



Water and loss 515 5.25 



10000 100*00 



The object of this analysis being to compare the nature and proportion.*; 

 at the constituent principles of amphibole and actinote, between which cry- 

 stallography had found a perfect analogy, the comparative resuU was such, 

 that it appeared necessary to blend them together under the same species oi 

 mineral, the latter presenting only some new varieties of colour of the for- 

 mer. — Trans. 



2B4 Roval. 



