392 RECORD OF SCIENCE FOR 1886. 



taiu that the molecnhir weights of all bodies, iiiorgauic or orgauic, can 

 be determined in like manner, provided the bodies are soluble in some 

 liquid capable of assuming a solid state at a temperature ascertainable 

 with accuracy. The meustruums employed are acetic acid, benzene, 

 and water. The methods of procedure and of calculation will be found 



in the original paper. (Ann. Chim. Phys. [6], viii, 317.) 



» 



On the Constitution of Acids, by W. A. Dixon.— The author proposes a 

 theory explaining the fact that some acids form with the alkali metals 

 alkaline hydrogen salts, whilst the similar salts of other acids are acid. 

 He suggests that, as is the case with organic compounds, the hydrogen 

 in inorganic acids exists in combination in two states, first, with oxygen 

 as hydroxyl, and, second, with two oxygen atoms as oxyhydroxyl. He 

 thinks that where both these exist in one acid the hydrogen of the oxy- 

 hydroxyl is invariably replaced first, and therefore the principal acid 

 function is in connection with oxyhydroxyl. Examples are taken from 



OOH 



the acids of phosphorus ; orthophosphoric acid is probably P — OH, 



OH 



because the acid itself has strong acid properties; but these are imme- 

 diately neutralized by the replacement of the hydrogen of the oxyhy- 

 droxyl group by sodium, while the replacement of the hydrogen of one 

 hydroxyl group gives a salt having an alkaline reaction. In like man- 



OOH 



ner phosphorous acid may have the composition P — OH , and is dibasic; 



OOH H 



/ /OOH 



hypophosphorous acid is P — H ; and pyrophosphoric acid, P <' 



\ , \oon 



H p/«^H 



^ \0H. 

 /OOH /OOH , ^ 



Sulphuric acid may be S <( and sulphurous S ^ , the first 



\OOH ^OH 



forming acid and the second alkaline hydrogen salts with the alka- 



/OOH , . 

 line metals. Hyposulphurous acid may be S (^ , and is mono- 



/OOH ^ /OOH 



basic, Nitric acid may be N < ; metaphosphoric, P < , and 



\^ O ^ O 



/OOH 

 chloric, CI { . (Phil. Mag. [5], xxi, 127.) 



\o 



The Reactions heticeen Metals and Acids, by Henry E. Armstrong. — 

 In the course of a paper before the Chemical Society of London on the 

 " action of metals on acids," in which experiments were described at- 



