Scientific IntelUge^ice. — Mineralogy. 195 



the laminae. There takes place, therefore, at the moment when 

 it is produced, a movement in the molecules, which determines 

 each surface to assume the one or other electricity. — Annales de 

 CMm, tt de Phys., Nov. 1827. 



20. Botryogen^ a nexv MineralSpecies. — G. Rose has published 

 descriptions of some new varieties of form observed by him in 

 the tessular system of cr^'stallization ; Mr Haidinger, a descrip- 

 tion, with figures, of the different forms of red sulphat of iron, 

 which he names, from its botryoidal form, Boti-yogen; and 

 M. F. Tamnau, an account of the prismatic forms of Dichroite. 

 These memoirs are contained in No. S. for 1828, of Pc^gen- 

 dorfs Journal. 



21. Octahedral Borax. — It is well known that common borax, 

 which occurs in tetarto-prismatic crystals, contains 10 atoms of 

 water of crystallization, with a specific gravity of 1.740. Accord- 

 ing to Payen {Journ. de Chim. Med. 1828, No. 4. p. 153), it is 

 capable of assuming another form, the octahedral, and then it 

 contains only 5 atoms of water, has a specific gravity of 1.815, 

 and is harder than common borax. 



22. Blue colour of Dichroite., fiot characteristic Jbr it. — The 

 blue colour of dichroite does not appear to be characteristic, for 

 M. Tamnau says, he has seen many crystals which were nearly 

 transparent, of a pure white colour, in whatever direction in re- 

 gard to the axis they were viewed. When in this state, and if 

 the planes of the crystals are imperfectly seen, it is difficult to 

 distinguish them from quartz-crystal, with which they occur 

 imbedded on magnetic pyrites. — F. Tamncniy Poggendor/^s 

 Journal, No. 3. 1828. 



23. Borate of Barytes. — When this substance is melted, and 

 then cut and polished, it exhibits a high degree of lustre, and 

 closely resembles the topaz of Saxony. 



GEOGRAPHY. 



24. Union of the Atlantic and Pacific. — It appears by let- 

 ters from Amsterdam, that the project of cutting a canal, to 

 unite the Gulf of Meidco with the Pacific Ocean, is about to 

 be revived under the auspices of the Netherlands government, 

 which has entered into communication with the government of 

 Guatemala, or Central America, for that purpose. General Van 



k2 



