182 



Dr. A. Scott. 



[Mar. 23, 



The hydrogen required was made from 



1. Electrolysis of dilute sulphuric acid. 



2. „ hydrochloric acid. 



3. Action of steam on sodium. 



4. Palladium hydride. 



The oxygen was obtained from 



1. Re- crystallised potassium chlorate. 



2. Mercuric oxide. 



3. Silver oxide. 



All the results in which potassium chlorate was used as the source 

 of the oxygen gave low results, doubtless due to traces of chlorine 

 accompanying the oxygen even after passing through potassium 

 hydrate. The best oxygen was obtained from silver oxide, and the 

 best hydrogen from palladium hydride. The palladium used com- 

 bined with enough hydrogen to perform twelve experiments in suc- 

 cession. The results of the last series are given in the following 

 table. The oxygen required was obtained from silver oxide. 



Column A contains number of experiment. 

 ,, B contains date of experiment. 



,, C contains measured volume of hydrogen in grams of mer- 

 cury. 



,, D contains measured volume of oxygen in grams of mer- 

 cury. 



,, E contains excess of hydrogen in grams of mercury. 

 ,, F contains excess of oxygen in grams of mercury. 

 „ G contains impurity in grams of mercury. 

 „ H contains number of volumes of hydrogen which unite 

 with one of oxygen. 



A. 



B. 



C. 



D. 



E. 



F. 



a. 



H. 



XXV 



Ap. 



1 



6863 



•8 



3443 



•8 





15 -4 



0-3 



2 



•0020 



XXVI 



1 



6870 



■o 



3432 



•9 





21 







2 



•0024 



XXVII 





2 



6870 



•1 



3439 



•7 





9-2 







2 



•0026 



XXVIII 





4 



6848 



7 



3422 



•1 





2-9 







2 



■0030 



XXIX 





4 



6792 



•5 



3386 



6 



13 -5 









2 



•0022 



XXX 





5 



6809 



2 



3399 



5 



1-5 









2 



•0025 



XXXI 





6 



6793 



9 



3399 



6 





7-7 







2 



•0029 



XXXII 





6 



6789 



•6 



3389 



•5 



2*9 









2 



•0023 



XXXIII 





7 



6808 



•5 



3396 



•4 



6 









2 



•0028 



XXXIV 





8 



6793 



•1 



3395 



•8 





2 1 







2 



•0017 



XXXV 





8 



6786 



5 



3395 



•o 





5-4 







2 



•0022 



XXXVI 





9 



6814 



■8 



3411 



•9 





9 3 







2 



•0028 



Mean = 2'00245 ± 0-00007. 



