Mathews, after a careful study of the osmotic behavior of blood plasma and saline solutions, has shown that the ordinary salt solution, which has been usually made in proportion of 6 to 1000, is not the best which can be used for purposes of saline infusion. Many observers have added potassium and calcium salts to such a mixture, the latter, especially, because of its property of increasing the coagulability of the blood. The following mixture meets the indications for what may be called the “balanced” physiological solution: Sodium chloride 0.9, potassium chloride 0.03, calcium chloride 0.02, water 100.[6] [6] To the fluid for hypodermoclysis (salt solution) there may be added a proportion of grape sugar, by which much is gained of true nutritive value, which may be enhanced by the addition of pure pepsin peptone free from albumose. Thus if every four hours there be injected beneath the skin 100 Cc. of water containing 2 grams each of grape sugar and table salt to 4 grams of pepsin peptone, the necessity for further nourishment may be almost obviated, at least for a period of two or three days at a time; as for instance when intense nausea of severe peritonitis prevents the ingestion of anything possessing food value. Credé recommends for the same purpose a preparation containing soluble albumin in the strength of 95 per cent., with traces of iron and salt. This preparation is called by him kalodol, and much resembles blood albumin, which is why it is so easily assimilated. According to Credé, four injections of kalodol a day will suffice for ordinary needs. It must not be forgotten that indiscriminate resort to intravenous infusion may do great harm. It is a minor procedure which requires skill. When the lungs are congested from the irritating effect of ether, and the right heart is embarrassed, a too sudden flushing with saline solution may further embarrass it or even check its activity. So with a patient in the Trendelenburg posture, the intestines are crowded up against the diaphragm and its natural downward play impeded, though the brain is better supplied with blood in this than in any other position. Much may be done in the way of _prevention_ when shock can be foreseen. This includes the general fortification of the patient by overcoming any auto-intoxication which may have been previously noticed, by improving elimination, and by stimulating the heart’s action with strychnine, digitalis, cactus, etc. Atropine is especially a stimulant to the respiratory centres.