1811.] 
decided on. The difficulty of finding any 
multiple of the quantity of oxygen which 
may be supposed to-exist in hydrogen, 
that might be applied to explain the com- 
position of nitrogen trom the same basis, 
1s against the simplest view of the subject. 
** But, still the phlogistic explanation, 
‘that the metal of ammonia is merely a 
compound of hydrogen and nitrogen, or, 
that a substance which is metallic, can 
be composed from substances not in their 
own nature metallic, is equally opposed 
to the general tenour of our chemical 
reasonings.” 
Mr. Brawpe has laid before the Society 
some observations, accompanied with 
cases and experiinents, on the effects of 
magnesia in preventing an increased 
formation of the uric acid; with remarks 
on the composition of urine.. Mr. Home’s 
enquiries into the functions of the sto- 
mach led him to consider that the gene- 
‘rality of calculous complaints might pos- 
sibly be prevented, by introducing into 
the stomach such substances as are ca- 
pable of preventing the formation of the 
uric acid. On putting this theory to the 
test of experiment, it was found, by an 
examination of the urine, that, in several 
instances where there was an increased 
formation of uric acid, magnesia dimi- 
nished it in a much greater degree than 
had been effected by the use of the alka- 
lies. The paper read before the Royal 
Society contained the result of Mr. 
Home’s and Mr. Brande’s labours, with 
a view to establish a fact of so mach im- 
portance in the treatment of those dis- 
eases. One case mentioned, is that of a 
(aa 
gentleman sixty years df agé,~who had 
been in the habit of indulging in she free 
use of acid liquors, had repeatedly'passed 
small calculi composed entirely of uric 
acid; his urine at all times deposited a 
considerable quantity of that substance 
in the form of red powder, and occasion- 
ally in larger crystals. The alkaline me- 
dicines were tried, without effect, though 
continued a year and upwards. ‘The 
patient was directed to take fifteen grains 
of magnesia three times a-day, ip an in- 
fusion of gentian: in a week the uric 
2cid was found to have diminished in 
quantity, and the use of magnesia being 
persevered in for eight months, there were 
during that time no calculi voided, nor 
any material deposit in the urine. The 
Proceedings of Learned Societies. 545 
patient was also much troubled with 
heart-burn, and with a sense of weight: 
and uneasiness about the region of the 
stomach, both of which symptoms like- 
wise disappeared, 
In another case the gentleman had 
during fou years occasionally voided 
considerable quantities of uric acid in 
the form of red sand, and had once 
passed a small calculus. His urine was 
generally more or less turbid,’ and after 
taking any thing which disagreed with 
the stomach, even in a slight degree, 
thered sand often made its appearance. 
Tie made trial of the alkalies, but withouz 
success. He was now directed to take 
magnesia, in the dose of twenty grains 
every night. and morning, .in a_ little 
water: for three days his bowels were 
much reiaxed, but they afterwards be- 
came regular. He persevered in its use 
six weeks, and during that period his 
urine was several times examined, and 
was found to contain no superabundant 
uric acid, and he had not the slightest 
return of his complaint, though he had 
put himself under no unusual restraint of 
living. The other cases given in this 
paper are equally to the point; from which 
Mr. B. infers that the effects of magnesia 
taken into the stomach are in many res- 
pects different from those produced by 
alkalies, in those patients in whom there 
is a disposition to form a superabundaut 
quantity of uric acid. | 
We have now an account of some ex- 
periments with soda, magnesia, and lime, 
to ascertain the effects ou heaithy urine, 
when taken under the same circum. 
stances. With respect to the soda, the 
effect of the alkali upon the urine was 
at its maximum ina quarter of an hour 
after it had been taken into the stomach, - 
and in less than two hours, the whole 
alkali passed off. A similar conclusion 
was diawn from the experiment where 
soda with an excess of carbonic acid was 
used. 
The experiments on magnesia shew 
that, even in large; doses, it neither pro-- 
duces so rapid an effect upon the urine, 
nor sO copious a separation of the phos- 
phates, as the alkalies; and on this its 
value as a remedy in calcwous disorders 
seems materially to depend. The lime 
was found to be of but little use in com- 
plaints of thissort. 
- 
ABSTRACT 
