234 PROCEEDINGS OP THE AMERICAN ACADEMY 



1424 100.00 100.00 



In computing the results of the analyses the loss of weight by igni- 

 tion, 10.09 %, is of course taken to represent 2 (NHJ.p + H^O + 3 Hg, 

 in accordance with the equation given above. In the analyses the 

 quantity of hypophosphorous acid was determined by dissolving the 

 salt in a solution of sodic carbonate, and then adding bromine, which 

 with the aid of heat readily converts the hypophosphorous into phos- 

 phoric acid. The quantity of the former could not be determined 

 by means of potassic hypermanganate in an acid solution. Bromine 

 does not act sensibly upon acid solutions, and even an excess of nitric 

 acid effects an imperfect oxidation. These facts, taken in connection 

 with the relations of the salt to solutions of copper and silver, seem to 

 show that the stability of hypophosphorous acid is increased by its 

 combination with molybdic teroxide. The salt has, as stated, a strong 

 acid reaction, and the limit of the basicity of this class of compounds 

 still remains to be determined. The formula may also be written : — 



8 M0O3 . 2 {H„ . PO . (NH,0),} 2 H„0 + 2 aq. 



The constitution of hypophosphorous acid was first established by 

 Wiirtz. More recent investigations in organic chemistry have shown 

 that it is to be regarded as dihydryl-phosphinic acid, and that it forms 

 the initial term and type of an extensive series of organic acids, in 

 which the two atoms of hydrogen attached to the phosphorus are 

 replaced by methyl, phenyl, &c., and in which also arsenic may replace 

 phosphorus. I do not propose at present to proceed further in this 

 particular line of research, but will content myself with the statement 

 that a solution of dimethyl-arsinic (kakodylic) acid gives immediately 

 in one of 14:6 acid ammonic molybdate a beautiful colorless crystal- 

 line precipitate. It can hardly be doubted that this is a dimethyl- 

 arsino-molybdate belonging to the general type represented by the 

 formula 



m M0O3 . 2 {(CHj)^ . AsO . (OH)} n (NHJp. 



The structural formula of the hypophospho-molybdate above de- 



