J8!2 Royal Society. 



the same effects followed when a globule was thrown into 

 water: in both cases a great quantity of hydrogen gas was 

 rapidly liberated. When laid on a piece of moistened tur- 

 meric paaper, the globule seemed instantly to acquire an in- 

 tense heat ; but so rapid was its movement in quest of the 

 nioisturCj that no part of the paper was burnt, only an in- 

 tense deep red stain marked the course it followed, and 

 showed a re-production of alkali. The specific gravity of 

 the base of soda is as seven to ten of water : it is fixed in a 

 temperature of about 150°, and fluid at 180". Mr. Davy 

 nexf tried its effects on the phosphats, phosphurets, and 

 the greater part of the salts of the first and £ect)nd de- 

 gree of oxydizement, all of which it decomposed, seizing 

 their oxvgen, and reassuming its alkaline qualities. Tbc 

 specific gravity of this amalgam, after a nuuiher of experi- 

 ments, was found by means of a mixture of oil of sassafras 

 with distilled naphtha, in which a globule remained either 

 buoyant at top, or quiescent at bottom, in a fluid weighing 

 as nine to ten of water. 



The sixth section of this lecture detailed a great variety 

 of experiments made to ascertain the difference of the base 

 6{ potash from that oisoda; and from the medium taken 

 of numerous analytical, and of nine synthetical, experiments, 

 it appeared that 100 parts of potash contain 15 oxygen, and 

 85 of inflammable base, and that the same quantity of soda 

 contains 20 oxvg^en, and 80 base. 



The seventh section was devoted to an examination of 

 volatile alkali, which chemists, led by systematic theory, 

 Lave rather hastily taken for granted that it consists merely 

 of hydrogen and nitrogen. Mr. Davy, after a great num- 

 ber of complex experiments, in which he was assisted by 

 Messrs. Pepys and Allen, ascertained that oxygen is also an 

 essential ingredient in ammonia, 100 grains of the latter 

 yieldinof 20 of the former : but this result depended too 

 much on eudiometrical calculation to be received as an 

 established fact. 



The eighth and last section consisted of general observa- 

 tions on the '* scries of 7iew facts" here disclosed, in which 

 Mr. D. related some miscellaneous experiments on the mu- 

 riatic 



