462 
DR. RONALDS ON SULPHUR AND PHOSPHORUS IN URINE. 
healthy subjects, and that the same excess of carbon passes off by the urine when the 
diet is more than usually rich in that element. From his paper however it does not 
appear that the quantity of this extractive or colouring' matter passed during a certain 
space of time has been ascertained, and it strikes me that he assumes the quantity of 
extractive to be the same in all kinds of urine ; this I think requires to be proved be- 
fore it can be positively affirmed that more carbon and hydrogen do pass off by the 
urine in such diseased conditions, as a larger quantity of less highly carbonized extrac- 
tive matter might compensate for the excess of carbon in the more highly carbonized, 
supposing the latter to be in less quantity. The relative quantity of these matters, 
and likewise the relative quantities of urea in a certain amount of urine, must be 
accurately determined before the conclusion can be considered as absolutely proved. 
Whilst engaged with the foregoing researches, it occurred to me that it might not 
be devoid of interest to the physiologist to know the amount of sulphur which was 
secreted by the kidneys in an unoxidized state. That urine does contain sulphur, not 
in combination as sulphate, is evident from the smell of sulphuretted hydrogen which, 
mixed with that of ammonia, is evolved from it whilst undergoing spontaneous decom- 
position, also from the blackening which white lead paint suffers when exposed to the 
gases arising from putrid urine, and likewise from the fact, that urine allowed to putrefy 
in a glass vessel containing oxide of lead as one of its contituents, permanently blackens 
the glass. To set the fact beyond doubt, two portions of urine, previously deprived 
of mucus by acetic acid and filtration, each consisting of four fluid ounces, were mea- 
sured ; the one simply evaporated and burnt, the other evaporated and afterwards de- 
flagrated with nitre. Each portion was then dissolved in dilute nitric acid, leaving a 
minute insoluble residue, and the sulphuric acid precipitated by chloride of barium; 
the results were as follows : — 
Four fluid oz., simply incinerated, gave 
grs. gr. 
o 
3 
= S 0-366. 
BaO SO, 2-656 = S0 3 0-902 
Four fluid oz., deflagrated 'with 
nitre, gave in grains 
BaO SO s 5-69/ = S0 3 T954 
= S 0-783. 
The quantity of sulphur in four fluid ounces not excreted in the state of sulphate 
was therefore 0-41/ grain. To ascertain the quantity of sulphur excreted by the 
urine in twenty-four hours in an unoxidized state, the whole quantity passed by three 
individuals during that time was collected on different days and measured ; its specific 
gravity was taken, and after being filtered from mucus, two portions of each speci- 
men were measured in a specific-gravity bottle containing 1000 grain measures ; one 
portion was simply acidified with nitric acid, and the sulphuric acid precipitated by 
nitrate of barytes. The other portion was evaporated with nitre and deflagrated, and 
the fused mass treated with dilute nitric acid and nitrate of barytes. From the dif- 
ference in the quantities of sulphate of barytes obtained, the amount of sulphur not 
in an oxidized state was ascertained. The results from five different experiments 
are shown by the following Table. 
