18:0.] 
of experiments upon the -decomposi- 
tion of considerable quantities of am- 
monia, in which nothing was present 
but the gas, the metals for conveying 
the electricity, and the glass; and every 
possible precaution used to prevent error 5 
and in all instances it was found, that 
there was no loss of weight of the appa- 
ratus, nor any deposition of moisture 
during or after the electrization, but the 
wires used were uniformly tarnisbed; and, 
im one instance in which surfaces of 
brass were used, a small quantity of 
olive-coloured matter formed on the 
metal; but though in this case nearly 
eight cubical inches of ammonia were 
decomposed, the weight of the oxidated 
matter was so minute as:to be scarcely 
sensible. In these experiments the in- 
crease of gas was uniformly from 100 to 
185, and the hydrogen was to the nitro. 
gen in the average proportions of from 
73°74 to 27°26; and assuming the com- 
mon estimations of the specific gravity 
of ammonia, of hydrogen, and nitrogen, 
Mr. Davy’s former conelusions are sup- 
orted by these new experiments: a3 
they were also when the relative specific 
gravities of these gases were taken with 
the utmost degree of precision possible, 
by means of the delicate balance belong- 
ing to the Royal institution, The speci- 
fic gravities thus taken are, 
Nitrogen, 100 cubical inches - 
Mydrogen = - - - 2°27 
Ammonia - ° - - 18-4 
The lately-discovered facts in chemis: 
try, says Mr. Davy, concerning the im- 
portant modifications which bodies may 
undergo_by slight additions or subtrac. 
tions of new matter, ought to render us 
cautious in deciding upon the nature of 
the process of the electrical decompo- 
sition of ammonia. It is possible, he 
adds, that the minute quantity of oxygen 
which appears to be separated, is not 
accidental, but a result of the decom- 
position, and if hydrogen and _ nitrogen 
be both oxydes of the same base, the 
possibility of the production of different 
proportions of water, in different ope- 
vations, might account for the variations 
observed: but on the whole, the idea 
that ammonia is decomposed into hy- 
drogen and nitrogen alone by electricity, 
and that the loss of weight is no more 
than 1s to be expected in- processes of so 
delicate a kind, is in his pinion, the 
most defensible view of ‘the subject. 
But it will be asked, If ammonia be ca- 
pable of decomposition into nitrogen and 
hydrogen? What is the nature of the 
29°8 grains 
Proceedings of Learned Societies. 
441 
matter existing in the amalgam of ammo. 
mia? and what is the metallic basis of the 
volatile alkali? These are questions not 
easily solved; but Mr. D. says, that, in 
his former communication on the amal- 
gam of ammonia, he stated, that, under 
all the common circamstances of its 
production, it scems to preserve a quan 
tity of water adhering to.it, which may 
be conceived to be sufficient to oxidate 
the metal, and to re-produce the ams 
monia. He is even unable to form it 
from ammonia in a dry state; neither 
the amalgams of potassium, sodium, or 
barium, produce it in ammoniacal vas; 
and when, they are heated with muriate 
of ammonia, unless the salt is moist, 
there is no metallization of the alkali, 
The amalgam, which he has reason to bee 
heve can be made most free from ate 
hering moisture, is that of potassium, 
mercury, and ammonium in asolid state: 
this decomposes very slowly, even in 
contact with water, -and when it has 
heen carefully wiped with bibulous paper, 
bears a considerable heat without alte- 
ration. ‘Lhe ratio between the hydrogen 
and ammonia produced from the .amale 
gan; is taken as one to two; and if this 
be accurate, then it will follow, that 
ammonia, supposing it to be an oxyde, 
must contain 48 per cent. of oxygen, 
which will agree with the relations of 
the attractions of this alkali fur acids to 
those of ether salifable bases. if hye 
drogen be a sinple body, and nitrogen 
an oxyde, then on the hypothesis above 
stated, nitrogen would consist of nearly 
48 of oxygen and 34 of base: but if hy- 
drogen and nitrogen are both oxydes of 
the same metal, then the quantity of 
oxygen in nitrogen must be less. _ These 
views are the most cbvious on the anti- 
phlogistic hypothesis of the nature of 
metallic substances; but if the facts 
concerning ammonia were reasoned upon, 
independently of other chemical pheno- 
mena, they might be more readily ex- 
plained on the notion of nitrogen being 
a base, which became alkaline by com- 
bining with one portion of hydrogen, and 
metallic by combining with a greater 
proportion. 
The solution of the question concerns 
ing the guantity of matter added to the 
mercury in the formation of the amalgam 
depends'on this discussion: for if the 
phiogistic view of the subject be adopted, 
‘the amalgam must be supposed to con- 
tain nearly twice as much matter as it is 
conceived to contain on the hypothesis 
of deoxygenation, Mr, D. did formerly 
Tale 
