the amalgam may, after washing, be transferred into the 
acid, the adhering water will nevertheless take up some 
more ammonia from the continuously decomposing substance 
while the hydrogen escapes. 
found a difficulty in obtaining consistent results, for he does 
proportions of the two gases. These are the words in which 
he sums up his observations : — “ As it does not seem possible 
to obtain an amalgam in an uniform state, as to adhering 
moisture, it is not easy to say what would be the exact ratio 
between the hydrogen and ammonia produced, if no more 
water was present, than would be decomposed in oxidating 
the basis. But in the most refined experiments which I 
have been ab]e to make, this ratio is that of one to two ; 
and in no instance in which proper precautions are taken, 
is it less ; but under common circumstances often more. if 
this result is taken as accurate ”, &c.* 
This statement of Davy’s being apparently the only 
authority for the assertion that the decomposing amalgam 
gives off the gases in atomic proportions, and yet being in con- 
flict with Gay Lussac and Thenard’s results, it appeared to me 
desirable to attempt to obtain more exact determinations. 
I used amalgam prepared by electricity in the manner 
described by Landolt. 
A simple mode of eliminating the disturbing effect pro- 
duced by the attraction of ammonia for moisture suggested 
metres long. At the bottom of the longer 
limb, just above the bend, there was an outlet 
tube to which was attached a piece of caout- 
chouc tubing closed by a pinch-cock. Mer- 
cury was poured into the tube until it filled 
It must be observed that Davy himself appears to have 
not seem to have ever entirely satisfied himself as to the 
itself. A U-shaped glass tube was provided, 
open at both ends, about 1*4 centimetres in 
diameter and having its shorter limb 40 centi- 
* Baker ian Lecture, 1809. 
