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ELEMENTS OF MATERIA MEDICA.

vital action ; and, if applied for a sufficient period, occasions mortification—an effect which is hastened by the previously weakened condition ofthe part. If applied to a large surface of the body, and for a sufficientlength of time, the processes of secretion, circulation, and respiration, arechecked, and stupefaction, followed by death, ensues.

When taken internally, the sensation of cold which it producesis not so obvious as that occasioned by its external application;and the effect is more temporary, from the greater heat of the in-ternal parts, by which the ice is sooner melted, and the resulting liquidquickly raised to the temperature of the body. If, however, it be takenin large quantity, the effects are of the same general kind as thosealready described; namely, a sensation of cold in the epigastrium, some-times attended with shivering ; diminished frequency of pulse; temporarycontraction of the alimentary canal; diminution of irritability, and ofsecretion. Employed in small quantities, these effects are not at allperceived, or are only momentary; and the second stage, or that ofreaction, almost immediately follows. Baglivi (quoted by Wibmer)found that the injection of four ounces of cold water into the jugular veinof a dog caused shivering of the whole body.

j3. Secondary effects. —When the application of cold is temporary,more especially if the subject be young and robust, reaction follows theremoval of the cold agent. The vascular action of the part is increased,the pulse becomes full and more frequent, and the animal heat is restoredto its proper degree, or is even increased beyond its natural standard.These effects, more or less modified, are observed both from the internaland external employment of ice. Thus, after the internal use of it, afeeling of warmth at the epigastrium soon succeeds that of cold, and thisextends shortly over the whole body; the secretions of the alimentarycanal, of the kidneys, and of the skin, are increased ; and the circulationis accelerated. Sometimes these secondary effects are attended with thoseof a morbid character: thus, inflammation of the stomach has beenbrought on by the employment of ice.

y. Effects of hot, but not scalding, water. —Hot, but not scalding,water increases the temperature and volume of living parts, relaxes thetissues, and augments vital activity. Applied to the skin it causes rube-faction.

o. Effects of boiling water and steam. —Both of these are local irri-tants, and, if sufficiently long applied, caustics, giving rise to extensiveand deep eschars. Steam contains more specific heat than boilingwater, but its conducting power is less than the latter.

Uses. —These may be subdivided into internal and external.—I. Internal, (a.) Of ice and ice-cold water. —Sometimes we admi-nister ice internally, for the purpose of obtaining its primary effects:thus, in haemorrhage from the stomach we use it for the purpose ofcausing contraction of the vessels of the gastric surface, and therebyof checking or stopping sanguineous exhalation. So also in violentpulmonary, or bronchial, or nasal haemorrhage, ice-cold water, taken intothe stomach, has been found beneficial. In most cases, however, w'e useit on account of its secondary effects. Thus, in relaxed and atonic condi-tions of the stomach—in dyspepsia and cardialgia, it is employed to checkvomiting, and to allay spasmodic pain. In those forms of fever deno-