VOLTAIC ACTION OF PHOSPHORUS, ETC. 289 



Permanent deflection of galvanometer, 8. 



Rise of liquid in oxygen tube, 0*35 cubic inch. 



,, in nitrogen tube, o. 



Weight of phosphorus = 2 '6 5. 



Taking a mean of these two experiments, which in their 

 relative results approximate more closely than I could have 

 anticipated under the circumstances, we get O'4i5 as the pro- 

 portional weight of phosphorus lost for a cubic inch of oxygen. 

 Now, as 24 31*4 :: 0*34 : 0^444. The result of these experi- 

 ments therefore leaves no doubt that phosphorous acid is the 

 product of the voltaic action, as it is of the slow combustion 

 of phosphorus in air. The experiment was repeated with dis- 

 tilled water ; the action was at first very trifling, but increased 

 every day, and the water gradually acquired an acid reaction. 



No light was apparent in any part of the apparatus when 

 examined in the dark ; indeed, the action was much too slow 

 to render such an effect probable ; though if subsequently by 

 heat or other means I should succeed, as I hope, in producing 

 light, it will be curious to observe in what part of the circuit 

 the luminous effect in the voltaic combustion is perceptible. 



A series of ten cells of phosphorus and nitrogen associated 

 with oxygen were charged, and perceptibly decomposed water 

 with platinum electrodes. 



The result of the above experiments gives, I believe, the 

 first instance of the employment of a solid, insoluble non-con- 

 ductor as - the excitant of a continuous voltaic current ; it 

 proves that the existence of diffused phosphorus in nitrogen, 

 as noticed by the old experimentalists, is not a consequence, 

 as was once believed, of a partial combustion, but of an effusion 

 continuing as long as the previously diffused phosphorus is 

 abstracted, and it gives the very curious result of a true com- 

 bustion, the combustible and the ' comburant* being at a dis- 

 tance ; phosphorus burned by oxygen which is separated from 

 it by strata both of water and gas, of an indefinite length. 

 This result, arrived at by a progressive series of inductions, 

 scarcely now appears extraordinary, but would have been in 

 all probability listened to with incredulity if simply stated as 

 a fact a few years ago. By the galvanometer we may also 



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