If the patient is sick, the vomited matter can be examined, but in the absence of sickness, lavage of the stomach should be performed an hour after an EwalcFs test meal. Before coming to a definite decision it is desirable that the analysis should be repeated several times.
The absence of free HCl is in favour of cancer, as is the presence of lactic acid, but the presence of some free HCl and the absence of lactic acid have no negative value.
In gastric carcinoma there is seldom found a normal amount of free HCl, and never an excess except in ulcus carcinomatosum ; the presence of an excess of free HCl is therefore decidedly in favour of ulcer.
In ulcus carcinomatosum, however, there is usually a large amount of free HC] in the stomach contents after a test meal.
In 90 per cent, of cases of cancer collected from various sources by Professor Osier there was an absence of free HCl in the stomach contents.