PECULIARITIES OF MEDICINES.

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The organized and inorganized kingdoms are distinguished from eachother by peculiarities of chemical composition, of form and structure, andof actions or functions.

1. Peculiarities of Chemical Composition.

Inorganized Bodies.

1. The undecomposed or elementarysubstances are fifty-four in number,—namely, oxygen, chlorine, bromine, iodine,fluorine, hydrogen, carbon, nitrogen, phos -phorus, sulphur, selenium, boron, silicon,potassium, sodium, lithium, magnesium, cal-cium, barium, strontium, aluminum, gluci-num, zirconium, yttrium, cerium, thorium,tellurium, arsenicum, antimony, chromium,uranium, molybdenum, tungsten, columbium,titanium, gold, silver, platinum, palladium,rhodium, iridium, osmium, mercury, bismuth,copper, tin, lead, cadmium, zinc, cobalt,nickel, manganese, iron, and vanadium.

2. Are sometimes simple, or elementa-ry; and, when compound, sometimescontain only two elements.

3. The compound atoms are capable ofdecomposition and of recomposition.

4. Are incapable of undergoing fermen-tation and putrefaction.

Organized Bodies.

1. The undecomposed or elementarysubstances are about twenty—namely,oxygen, chlorine, bromine, iodine, fluorine,hydrogen, carbon, nitrogen, phosphorus,sulphur, silicon, potassium, sodium, cal-cium, magnesium, aluminum, iron, manga-nese, gold, and copper. Of late it hasbeen asserted that titanium is present inthe renal capsules. Of the above-men-tioned twenty elements in organized be-ings, only three or four are met with inconsiderable quantity—namely, oxygen,hydrogen, carbon, and nitrogen.

2. Are never simple. Every living partcontains three or four elements at least,and frequently more.

3. Organised or living' parts may bedecomposed, but cannot be recomposed.

4. Are capable of undergoing fermen-tation and putrefaction.

2. Peculiarities of Form and Structure.

Inorganized Bodies.

1. The volume is variable and inde-finite.

2. The exterior form may be regular orirregular. When regular, these bodiesare bounded by straight lines, and haveangles ; in other words, the regular formof inorganized bodies is crystalline.

3. The internal arrangement of theparts, or the structure, may be regular orirregular. If solid and regular, it is crys-talline.

4. Are generally composed of solid, li-quid, or gaseous matter, exclusively:some exceptions, however, to this state-ment exist. Dr. Brewster has discoveredcolourless and transparent liquids in sometopazes, chrysoberyl, &c.

5. The separate parts are generallyhomogeneous, though sometimes hetero-geneous.

6. The separate parts are independentof each other.

Organized Bodies.

1. The volume is variable, but definite.Thus though animals vary in their size,there is a limit to the variation.

2. The exterior form is regular, andgenerally rounded. To this,however, wehave exceptions in some of the Diatomeee,which, at one period of their existence,are angular.

3. The internal arrangement of theparts, or structure, is regular. This regu-lar arrangement is vesicular or tubular.

4. Always consist of both solids andfluids. Mosses and certain animals (asthe Vorticella rotatoria and Vibrio An-guilla) may be dried without destroy-ing their vitality; and hence form ex-ceptions to this statement. But theyare probably never so dried as to bewholly deprived of moisture ; and, m thenext place, in this dried state they giveno sign of life ; for it is only by moisten-ing them that the vital phenomena be-come apparent. Moreover, Ehrcnbergdenies that animals can revive after desic-cation.— (Midler's Physiol, p. 33.)

5. The separate parts are essentiallyheterogeneous : that is, they possess dif-ferent properties.

6. The separate parts are always re-lated, and in some cases are dependent oneach other. This subserviency of one partto the other constitutes what is termedorganization, the parts being called organs.