1395 
ring-test on the patient’s serum. In that case the reaction was always 
positive, so that in this way the presence of hydrogen sulphid in 
the serum was established chemically. To make assurance double 
sure possible sources of error had to be precluded. For acetone and 
kreatinin also give a coloration with nitroprussid in ammoniacal 
solution. We detected, however, that, as regards acetone, this reaction 
turns out negative for a multiple of the largest possible quantities 
occurring in the bloodserum. A negative result was likewise obtained 
for two patients with pronounced acetonuria (diabetes). Similarly 
kreatinin yields with this reagent a positive result only in a multiple 
concentration of the largest possible quantities occurring in the serum. 
Moreover the colour of the kreatinin-ring differs widely from that 
of the hydrogen sulphid ring. Finally we have examined in the 
same way the serum of a certain number of normal persons. The 
result was negative. 
In order to get more certainty that it was sulphaemoglobin we 
had detected, we proceeded as follows. A little of the patient’s blood 
was collected in a physiological common-salt solution and washed 
out with it repeatedly, so that all the serum was removed. The 
spectrum of the red bloodcorpuscles appeared to have retained the 
sulpho-band, while the pipetted liquid did not yield a reaction with 
Krat’s reagent. 
We now added to a mixture of red bloodeorpuseles and physio- 
logical saltsolution a little of a 2°/, potassium cyanid solution (neu- 
tralized and in physiological NaCl solution to prevent haemolysis). 
The mixture was placed some time in the incubator. After some 
hours the HCN had expelled the H,S; the SHb-spectrum had made 
room for that of CyHb and in the supernatant fluid we obtained a 
positive reaction with nitroprussid *). 
It would seem, then, that hereby the presence of H,S, be it only 
in small quantities, in the serum as well as in the blood-pigment 
of our patient, had been established. 
Earlier experiments of Craupe BERNARD have demonstrated that 
hydrogen sulphid injected intravenously into animals, is exhaled 
through the lungs. Although, comparatively speaking the quantities 
of H,S in the blood of our patient are not inconsiderable, we 
did not succeed in demonstrating in this simple manner H,S in 
the exhaled air. We did get a positive result, however, when the 
boy had been breathing for + one hour in a specially contrived 
1) When prosecuting our investigation we found this phenomenon to be of a 
more complex nature than can be anticipated from the description given in this 
paper. 
