364 Scientific Intelligence. 



40. New Crystalline form of Laumonite.— This mineral was found by 

 Dr Bigsby at three different places on Lake Superior. The crystallized 

 variety was discovered in a small vein of white calcareous spar and red 

 feldspar. Its form is a rhomboidal prism, acuminated with a dihedral sum- 

 mit.— Id. p. 53. 



41. Farther Observations relative to Kupffhers Law in Mineralogy. —In 

 vol. iv. pp. 186—188 of this Journal, we laid before our readers an account 

 of the remarkable law in mineralogy, announced by M. Kupffner. The 

 following consequences of this law have been deduced by M. Vincent : 



1. The cubes of the axes of primitive forms, which contain the same 

 number of atoms, are in the inverse ratio of the squares of their specific 

 weights. 



2. In crystalline substances, of the same primitive form, the specific 

 weights are in the inverse ratio of the weights of the atoms. 



3. The squares of the weights of the atoms are proportional to the cubes 

 of the axes of the primitive form. 



4. The cubes of the respective distances of the atoms, in two substances 

 of the same primitive form, are proportional to the squares of the weights 

 of these atoms, or in the inverse ratio of the squares of these specific 

 weights. — See Ann. de Chim. torn. xxxi. p. 104. 



42. Pholerite, or Silicate of Alumina. — This substance frequently occurs 

 in the coal formations of Fins, (dep. of Allier,) in fissures in the ironstone. 

 It occurs in small convex nacreous scales : It is soft and friable, and adhe- 

 sive to the tongue, and is of a pure white colour. It is composed of 



Silica, - - 41.775 



Alumina, - - 43.104 



Water, - - 15.121 



100.000 

 Ann. des Mines, vol. xi. p. 489. 



geology. 

 43. Bowlders exhibiting Scratches and Furrows on their lower surfaces. 

 — " I have had occasion, says Mr P. Dobson of Vernon, Connecticut, to 

 dig up a great number of bowlders of red sandstone, and of the conglome- 

 rate kind, in erecting a cotton manufactory ; and it was not uncommon to 

 find them worn smooth on the under side, as if done by their having been 

 dragged over rocks of gravelly earth, in one steady position. On examina- 

 tion, they exhibit scratches and furrows on the abraded part; and if, 

 among the minerals composing the rock, there happen to be pebbles of feld- 

 spar or quartz, (which was not uncommon,) they usually appeared not to be 

 worn so much as the rest of the stone, preserving their more tender parts 

 in a ridge, extending some inches. When several of these pebbles happen 

 to be in one block, the preserved ridges were on the same side of the peb- 

 bles, so that it is easy to determine which part of the stone moved forward, 

 in the act of wearing." Some of these blocks weighed fifteen and even 

 thirty tons. These curious facts confirm the ingenious speculations and 



