150 



and the two divisions have a tendency to rotate in opposite direc- 

 tions. The character of these two forms of electrical discharge can 

 always be determined by the magnet. 



The author concludes his paper in the following words : " I refrain 

 for the present from any observations as to the action of the magnet 

 on the discharge. The intimate relation of magnetic and electric 

 action has long since been shown; but the curious effect of the 

 power of a magnet to draw out the stratifications from the positive 

 terminal, and in some instances its powerful action on that portion of 

 the discharge which exhibits the phosphorescent light in its great- 

 est intensity, are worthy of further examination. In the preceding 

 experiments my object was directed to the examination of the stra- 

 tified and of the dark band discharge ; at present I am inclined to 

 the opinion that the stratifications in the positive, and the dark band 

 between it and the negative glow, although apparently similar, are 

 effects arising from distinct causes the former from pulsations or 

 impulses of a force acting in a highly attenuated but resisting 

 medium, the latter from interference. I am at this time engaged in 

 making further experiments for the elucidation of this novel and 

 remarkable phenomenon." 



March 11, 1858. 

 Dr. HOOKER, Vice-President, in the Chair. 



The following communications were read : 



I. Notes of Researches on the Poly- Ammonias. By AUG. W. 

 HOFMANN, Ph.D., F.R.S. &c. Received February 4, 1858. 



Former investigations had led me to some general conclusions re- 

 garding the molecular constitution of the organic bases, which I have 

 communicated to the Royal Society, and which have been published 

 in the 'Philosophical Transactions' (1850, p. 93; 1851, p. 357). 

 My experiments had proved that each equivalent of hydrogen in 



