In the pyloric stenosis of infants, quantitative changes are frequently found in the chemical constituents of the plasma. Thus, the alkali reserve may be increased, while the chloride content is often lowered (Hartmann and Smyth,1 Maizels, McArthur and Payne2). The object of the following investigations was to determine whether similar changes occurred in the cell chloride, and whether such changes were relatively more or less marked.
The foot is warmed if necessary, and blood is obtained by puncture of the great toe. The flow is usually fairly free, and the capillary blood, as a rule, is well oxygenated. The pH of a sample of blood is determined by Martin and Lepper's method,3 and the rest is allowed to flow under liquid paraffin in a small tube of the type described by Martin and Lepper.4 Heparin is used to prevent clotting. The blood is centrifugated