150 Proceedings of Fiiilvscp/acat Societies. [Feb. 



The fixed alkalies, barytes, strontites, and lime, have been 

 supposed to contain combined water, essential to them in their 

 insulated form. It is probable that the elements of water rather 

 exist in direct combination with their metallic base ; that potash, 

 for example, is a ternary compound of potassium, oxygen, and 

 hydrogen. And thus the entire class will exhibit the same rela- 

 tions as the class of acids ; some being compounds of a base with 

 oxygen ; ammonia a compound of a base with hydrogen ; and 

 potash, soda, &c. compounds of abase with oxygen and hydrogen. 

 And these last, like the analogous order among the acids, exceed 

 the others in power. When an acid and alkali unite, the 

 hydrogen of both is expended in forming water. The neutral 

 salts, therefore, according to these views, will be either sur- 

 compounds of two binary compounds, one of the radical of the 

 acid, the other of the radical of the base with oxygen ; or they 

 are ternary compounds of the two radicals with oxygen. The 

 latter is the more probable opinion. 



At the same meeting, Dr. Brewster communicated a veiy 

 interesting paper, consisting of extracts of letters from Mr. Boog 

 to his father, the Rev. Dr. Boog, of Paisley, giving an account 

 of the recent discoveries respecting the sphinx, and the principal 

 pyramid of Egypt, which have been made by Captain C. and Mr. 

 Salt. By very laborious excavations, which were made in vain 

 by the French savans, these gentlemen have discovered, that 

 the sphinx is cut out of the solid rock on which it was supposed 

 merely to rest. They found that the short descending passage 

 at the entrance to the pyramid, which afterwards ascends to the 

 two chambers, was continued in a straight line through the base 

 of 1 he pyramid, into the rock upon which the pyramid stands. 

 This new pas '-.age, after joining what was formerly called the 

 well, is continued forward in a horizontal line, and terminates in 

 a well ten feet deep, exactly beneath the apex of the pyramid, 

 and at the depth of 100 feet below its base. Captain C. has 

 likewise discovered an apartment immediately above the King's 

 chamber, and exactly of the same size and the same fine work- 

 manship, but only four feet in height. 



Jan. 19. — The second part of Dr. Ure's paper on Muriatic 

 Acid Gas was read. In this part the author showed that the 

 azote of the ammonia has no concern in the production of the 

 water ; for the whole azote, competent to the weight of salt 

 employed, is recoverable in a gaseous form. It is then experi- 

 mentally demonstrated, that the sal-ammoniac, resulting from 

 the union of the two dry constituent gases, yields water in 

 similar circumstances. No water could "be obtained, however, 

 by heating dry sal-ammoniac alone, or in contact with charcoal, 

 or even by passing its vapour through ignited quartz powder. 

 Hence Dr Ure infers, that the traces of moisture, formerly 

 observed by Dr. Murray, on exposing sal-ammoniac to heat, 

 must have been the hygrometric water of the imperfectly dried 



