In addition to their action on the intestine and in some cases the kidney and salivary gland, these salts produce an interesting condition of the voluntary muscles. As mentioned above, Loeb was able to produce muscular twitchings in the muscle of a frog by immersing the muscle in solutions of these various salts. He also produced muscular twitching in a living frog by injecting sodium citrate into the dorsal lymph sacs. I have found that a subcutaneous injection of 10 c.c. m/1 sodium citrate produces in a rabbit well marked twitchings of the muscles all over the body. These are very noticeable in the gluteal region. They begin almost immediately in the neighborhood of the injection, but only after an interval of 20 to 25 minutes on the opposite side of the body. If the animal be placed on the floor it moves with a peculiar incoördinated gait. The hind legs are dragged and very little headway is made. If the rabbit be held up by the ears, the feet tremble, and if touched the legs jerk away violently and usually become rigid. There are sometimes tetanus-like contractions of the limbs, and occasionally general convulsions of greater or less severity. In one rabbit I gave daily injections of 5 c.c. m/1 sodium citrate subcutaneously throughout one month. For some time after the injections had been discontinued the hypersensitiveness seemed to persist. It seemed possible from this that a chronic state of increased irritability might be produced. No conclusion, however, can be drawn from this one experiment since the irritation caused by the repeated injections might have had some influence. It is a subject which is of interest for further experiment, on account of the similarity such a chronic condition bears to the various chronic hypersensitive conditions found in human beings. In looking over the experiments made by various investigators on this subject it will be noticed that their results are inconstant and contradictory. This can only be the result of imperfect technique and unfavorable conditions, or of the adoption of a criterion of the action of the salt, which is uncertain. As mentioned above, the solutions used in many cases were not at all those most favorable for introduction into the blood. The very concentrated solutions used by Hay rendered the conditions obviously unfavorable. If in addition to watching for the actual passage of faeces these experimenters had observed the intestines directly the results would of necessity have been more uniform.