I believe these figures are as nearly accordant with the 

 atomic proportions as could be expected from the means 

 employed, where the possible error in determining the 

 volumes might amount to perhaps '2 c.cm. 



In another similarly conducted experiment, in which it 

 was sought to obtain as much gas as possible, the tube was 

 closed too soon, and the result showed a deficiency of 

 ammonia, but is otherwise interesting : — 



Experiment 5. 



A new observation on the amalgam has recently been 

 made in America by Professor C. A. Seeley,* who found, by 

 subjecting it to varying pressure that its volume changes, 

 apparently in accordance with Mariotte's law. He employed 

 simply a glass tube fitted with a plunger, and did not 

 measure the pressures or volumes. His conclusions were 

 that the amalgam is a mechanical or physical mixture of 

 liquid mercury with the gases ammonia and hydrogen, and 

 that its semifluid consistence is due to the mixture having 

 the nature of a froth. 



Being desirous of submitting Seeley's remark on the com- 

 pressibility of the amalgam to the test of direct measure- 

 ment, I subjected the electrically formed amalgam to 

 pressure in a glass tube 48 centimetres long and I'S centi- 

 metres diameter. The pressure was applied by connecting 

 the tube with a syringe, by which air could be forced into 



* Chem. Neios, June lOtb, 1870. 



