Page:The American Cyclopædia (1879) Volume VI.djvu/165

 DIVISIBILITY DIVORCE 157 is a forked slender stick of witch hazel ; elastic twigs, however, of any sort, or even two sticks of whalebone fastened together at one end, are sometimes employed. One branch of the twig is taken in each hand between the thumb and fore finger, the two ends pointing down. Hold- ing the stick in this position, the palms toward the face, the operator passes over the surface of the ground ; and wherever the upper point of the stick bends over and points downward, there he affirms the spring or metallic vein will be found. Some even pretend to desig- nate the distance below the surface according to the force of the movement, or according to the diameter of the circle over which the ac- tion is perceived, one rule being that the depth is half the diameter of this circle ; whence the deeper the object is below the surface the further is its influence exerted. The experi- ment being tested by digging, if water is found it proves the genuineness of the operation ; if it is not found, something else is, to which the effect is attributed ; or it is declared that the water which attracted the rod is sure to be met with if the digging is continued deep enough. DIVISIBILITY, one of the general properties of matter, usually classed with impenetrability, extension, &c. The proposition that there is no limit to the mathematical subdivision of matter is universally admitted ; but the ques- tion in its relation to physical science is a dif- ferent one, and its treatment depends upon the adoption of one of two theories. Formerly it was not infrequently supposed that matter is continuous; at least, the idea that it consisted of ultimate atoms of a definite magnitude, and therefore that each body was composed of a certain limited number of them, was not en- tertained. According to the old doctrine of the homogeneity of matter, therefore, its divisi- bility physically could only be limited by the means employed, and in a theoretical point of view was logically considered as infinite. But the doctrine of Dalton in regard to definite and multiple proportions has been so well estab- lished by the investigations of chemistry, and researches into the molecular constitution of matter, particularly gaseous bodies, that physi- cists now generally hold that the subdivision of matter is limited physically, that at last the atoms become separated from one another, and these being the primordial particles, no con- ception can be formed of any subdivision of them. As examples of the great extent to which subdivision may be carried without ar- riving at the ultimate atoms, or even at the molecules of which they are composed, may be taken the spinning of the spider's web, which contains 4,000,000 fibres, which of course are composed of organic molecules of a compound structure, spun together within the diameter of a human hair ; the odor of musk, which may pervade a room for years by the exposure of only a single grain ; and the extent to which sulphuret of lead may be diffused by adding together solutions of almost infinitesimal quan- tities of a salt of lead and sulphuretted hydro- gen. Dr. Thomson in this way obtained sul- phuret of lead in quantities sensibly appre- ciable, but which must, according to his com- putations, have been divided into at least 500,- 000,000,000 parts; and yet it is uncertain whether this division extended to the binary molecules of the substance. The most striking examples, however, of the extent to which matter may be divided, and at the same time manifest its presence by the exhibition of a degree of energy, are furnished by the ex- periments of Tyndall with minute quantities of gases, vapors, and perfumes, in which he exhib- its their influence upon the diathermancy of at- mospheric air and the elementary gases. He found that a quantity of watery vapor so small as to be inappreciable by any other test would increase the absorptive power of dry air to the obscure rays of heat to such an extent as to cause a marked difference in the deflection of the needle of a galvanometer. The equality which he has also established as existing be- tween the diathermancy of the elementary gases and their mechanical mixtures, indicating that their elementary particles assume uniform and therefore definite wave vibrations, when in a free state they are subjected to the action of uniform heat waves, has thrown so much light upon the subject of molecular physics that the conclusion that elementary atoms or primordial particles limit the divisibility of matter cannot be resisted. DIVORCE, a dissolution of the bond of mat- rimony for cause occurring after marriage. In popular language, however, and often in judicial discussions and statutes, another class of cases is included, namely, those in which a marriage is annulled for antecedent causes ren- dering it void or voidable. The common law allowed divorces causa impotentice sen frigidi- tatis, if such impotence or frigidity existed before marriage, this being deemed a fraud ; but it was no ground of divorce if it supervened after marriage ; and it is the only kind of fraud of which we find mention in the English cases as a ground of annulling a marriage. Fraudu- lent representations by either party in respect to his or her condition in life, pecuniary cir- cumstances, family connections, bodily health, and the like, however material these may have been in inducing a consent to the contract, still are unavailable as an impeachment of the marriage. A false personation of another, or any fraud by which one of the parties is de- ceived in respect to the person with whom the marriage is solemnized, is a sufficient cause for annulling the marriage ; but this is put upon the ground of want of consent, it being equally essential to this as to other contracts that there should be the animus contrahendi, and the contract cannot take effect contrary to the real intention of the party who is to be bound. In the English courts the proceeding causa jac- titationis matrimonii was intended for relief in such cases ; in form, being an action by the