88 Prof. G. Quincke on the Constants of 



convenient to use the glass-blower's flame instead of that of an 

 ordinary Bunsen. 



Selenium. 



Tin. 



Zinc. 



2r. 



rniilim. 



W. 



grm. 



«. 



i 2, 



W. 



«. 



*. 



W. 



a. 



mgrms. 



millim. 



grm. 



mgrms. 



millim. 



grm. 



mgrms. 



0-9670 



00214 



7045 



0-665 



0-1200 



57-41 



0-8368 



0-2122 



80-74 



07164 



00158 



7-021 



[ 0-642 



01245 



61-69 



0-7285 



01920 



83-90 



0-6688 



0-0155 



7-377 



1 0549 



0-0976 



5652 



0-7020 



0-1847 



83-75 



0-6125 



00140 7-27' 



0-470 



0-0800 



54-25 















0-437 



0-090 



65-39 















0072 



58-08 















0-311 



0-064 



65-62 









Mean 



7-180 





Mean 



59-85 





Mean 



82-79 



8. In the case of bodies which, like phosphorus, cadmium, lead, 

 antimony, bismuth, [oxidize easily, it was necessary to produce 

 the drops in an atmosphere of carbonic acid. In the case of 

 zinc also, where oxidation might have been suspected in the open 

 air, several of the experiments were performed in an atmosphere 

 of carbonic acid, which demonstrated that the capillarity-con- 

 stants are little, if at all, dependent on the nature of the sur- 

 rounding gas when the surface is not altered by oxidation. 



The phosphorus was melted in a test-tube under water, a ball 

 of india-rubber fastened on the glass tube which had been drawn 

 out into the shape of a pipette, and the molten phosphorus 

 sucked up by pressure on this ball. The glass pipe was care- 

 fully dried on the outside with blotting-paper. In these ex- 

 periments it often happens that the phosphorus remains in a 

 fluid state far below its melting-point, and that we find the 

 weight of the drop or the capillarity-constant too large. Pos- 

 sibly the abnormal result given by Dupre*, who found u = 8*407 

 milligrammes for 46° C, a number about twice as large as that 

 which is deduced from my experiments, is to be explained in this 

 way. The drops taken up under water remain also fluid for a 

 considerable time ; and it happens frequently, when they follow 

 each other quickly, that several gather themselves into one, 

 which then itself continues fluid for a considerable time. In 

 the determination of the constant of capillarity it is natural in 

 this case to take account of the number of drops which have 

 been collected into one. 



Zinc and antimony were molten in the flame of the glass- 

 blower's lamp, cadmium and lead in that of a Bunsen's burner. 



The carbonic acid was obtained from marble and hydrochloric 

 acid, led through a washing- bottle with a solution of carbonate 

 of soda and a series of Babo's bulb-tubes, which were also 

 * Ann, de Chim. et de Phys. vol. ix. (1866) pp. 330 & 384. 



