1823.] Mr. Levy on a new Mineral. 243 



been the result of intermediary decrements. For a similar 

 reason relative to the face e 3 , I have determined the ratio 

 between the lateral edge and one side of the base by assuming 

 e 1 to be the result of a decrement by one row on the lateral 

 angles of the base. The cleavage I have mentioned before is 

 parallel to a plane passing by the two small diagonals of the 

 bases. The decrements which produce the other faces are 

 indicated by the signs written upon them ; and their incidences 

 upon p or m are as follow : 



It will not be, perhaps, useless to remark, that in the oblique 

 rhombic prism I have adopted for the primary form, the line 

 joining the angle o with its opposite is not perpendicular to the 

 edge h. A perpendicular drawn from o upon the edge opposed 

 to h would cut that line at a distance from a, a little less than the 

 two-thirds of the length I have assigned to it. 



I am, yours, &c. A. Levy. 



Article II. 



Researches into the Mathematical Principles of Chemical Philo- 

 sophy. By the Rev. J. B. Emmett. 



{Concluded from vol. iii. N. S. p. 433.) 



Great Ouscbum, Feb. 22, 1823. 



Sect. II. On the Construction of Liquids. 



Lemma 1. — When the repulsive force of heat in a solid 

 exceeds the force of cohesion, its particles will be separated 

 from each other. 



Lemma 2. — If there be two curves having a common axis, 

 and on the same side of it, whose ordinates are inversely as 

 some given powers of their abscissa? ; that curve whose ordi- 



k2 



