872.] Dr. A. W. Hofmann on the Phosphorus Bases, 221 



smooth, the other rough with electrolytically-deposited copper ; these 

 were separated from thin plates of zinc merely by pieces of muslin, and the 

 metals were folded over at each end and hammered together. Each couple 

 was placed in water, and for some days very minute bubbles of gas formed, 

 but only at the junction of the metals, and about equally in each case. 



As might be expected, this zinc in conjunction with copper is capable 

 of decomposing other liquids than water. Chloroform yields readily to its 

 power, and iodide of ethyl, which Prof. Frankland decomposed by zinc 

 only at a great heat, is split up rapidly at the ordinary temperature. 



March 21, 1872. 



WILLIAM SPOTTISWOODE, M. A,, Treasurer and Vice-President, 



in the Chair. 



The following communications were read : — 

 I. " New Researches on the Phosphorus Bases." By A. W. Hofmann, 

 LL.D., P. U.S., Professor of Chemistry in the University of 

 Berlin. Received March 6, 1872. 



About twelve years have elapsed since I submitted to the Royal So- 

 ciety, partly in conjunction with M. Cahours, a series of papers* on the re- 

 markable group of phosphorus compounds, the existence of which was first 

 pointed out by M. Paul Thenard as far back as 1846. These researches 

 were devoted to the investigation of the tertiary and quart ary derivatives 

 of phosphoretted hydrogen, exclusively accessible by the methods then 

 at our disposal. The study of the primary and secondary phosphines, 

 the examination of which promised even more noteworthy results than that 

 of the bodies then investigated, still remained to be achieved. 



New tasks of life have since that time presented themselves, and I have 

 not been able to devote myself as much to research as in former days. 

 Nevertheless, numerous attempts were made to procure the primary and 

 secondary phosphines, which were clearly indicated by theory and partly 

 even by M. Thenard's early observations. For along time, however, these 

 experiments proved unsuccessful, and it was only in the course of last 

 summer that I at last discovered an easy method for their production. I 

 may now fairly hope to complete an inquiry, the first part of which the 

 Royal Society have done me the honour of inserting in the ' Philosophical 

 Transactions' f; still some time will be required for surveying a field which 

 appears to expand as one advances in its investigation, and I therefore beg 

 leave to present to the Society the results of my observations in the measure 

 as they are obtained, even before the whole investigation be terminated. 



* Proceedings, vol. viii. pp. 500, 523 ; vol. ix. pp. 287, 290, 487, 651 ; vol. x. pp. 100, 

 189, 603, 608, 610, 613, 619 ; vol. xi. pp. 286, 290. 

 t Phil. Trans. 1857, p. 575 ; 1860, pp. 409, 449, 497. 



