As stated above, it was shown by Claude Bernard and by Pflüger that section of the spinal cord below the phrenic nerve, or section of the splanchnic nerves, causes a marked increase in the intestinal movements, and also an increase in the amount of fluid secreted (Moreau). These movements continue in loops isolated and removed from the body and placed in m/6 NaCl, LiCl, Na_{2}SO_{4}, sodium citrate, etc., for varying periods of time. They continue far longer in NaCl than in any other solution. Calcium chloride inhibits these movements, as is the case also with magnesium chloride. It was found,[61] however, in making these experiments with isolated loops removed from the body, that with certain mixtures of NaCl or LiCl with CaCl_{2} or MgCl_{2}, movements began after 20 or 25 minutes of a character differing entirely from the movements seen in pure NaCl. An idea of this phenomenon may be gained from the following description of experiments. A word may be first said with regard to the methods used in these experiments. In rabbits anaesthetized as usual, the abdomen was opened and a loop 30-40 cm. in length isolated by ligatures. By means of a needle and thread the blood vessels supplying the loop were carefully tied and the loop rapidly excised. It was then cut into a number of pieces, usually four, which were transferred with as little handling as possible to the beakers containing the solutions to be tested. These beakers were kept in a water bath at 39.5° C. It is desirable in these experiments to use loops which contain no faeces, since unknown substances in the faeces might go into solution and disguise the action of the salt being tested. For this reason the upper part of the small intestine was principally used since in the rabbit it is usually empty or can be readily emptied. In each set of experiments the loops must all come from the same rabbit, for there exist considerable differences in irritability in different animals. On account of these differences it is necessary to have control experiments in the case of each rabbit. Loops also which have been unduly exposed to the air cannot be used. It is of great importance to keep the solutions at a constant body temperature. _(a) LiCl and CaCl_{2}._ A loop of intestine removed from the body and placed in an m/6 LiCl solution at body temperature usually exhibits only slight movements, which soon cease. This seems to vary somewhat with different rabbits. In some cases the loop shows no movements at all, while in other instances it moves regularly for half a minute and then comes to rest in the solution. These movements are quiet and regular and resemble those described in loops immersed in m/6 NaCl solution. When a loop has ceased to move it does not become active again. In exceptional cases these movements may last 5-10 minutes, but rarely longer. The LiCl solution seems less favorable for the long duration of the movements than the NaCl.