The amount of sodium citrate, sulphate, or tartrate necessary to produce purgation is about the same in each case: 10 c.c. m/6 solution injected subcutaneously, followed 10 minutes later by a second injection of 5 c.c. of this solution and 10 minutes after this by a third similar injection, usually produces well marked passages of faeces. Sometimes the result is obtained with a single injection, but a prolonged action of the salt seems to be more favorable. With sodium fluoride and barium chloride much smaller doses are necessary. Sodium fluoride is more poisonous than the citrate or sulphate, but if injected slowly as much as 10 c.c. m/6 solution can be safely introduced under the skin. This produces in a little over an hour well marked purgation, usually with the passage of soft or semifluid faeces. Barium chloride is a well known saline purgative among veterinary surgeons, who always administer it intravenously or subcutaneously. In order to purge a horse weighing 1,000 pounds, O.75 g. BaCl_{2} is usually given subcutaneously. Its action is very constant. When given to rabbits I have found that 2 c.c. m/6 solution BaCl_{2}, injected under the skin always produces a well marked purgative action with the passage of large quantities of semifluid faeces. When injected intravenously it is better to mix the BaCl_{2} with about five times its volume of m/6 NaCl. The injection of 1 c.c. of a mixture of 1 c.c. m/6 BaCl_{2} + 5 c.c. m/6 NaCl produces purgation and a passage of semifluid faeces. This action is much more rapid than with NaF. These experiments demonstrate the fact that the intravenous or subcutaneous injection of saline purgatives do produce purgation and an actual passage of faeces. In order, however, to study the action of the salts more minutely another method was resorted to, namely, that of opening the abdomen and directly observing the loops of intestine. In a large number of experiments it is not difficult to become quite familiar with the movements normally present, and with the disturbances produced by such external influences as cooling, drying, etc. These influences can by proper precautions be practically eliminated.