1882.] ^ ' "J [Chase. 



from the calculated values, in the other twenty-three comparisons, the 

 variability is moi'e than one per cent, in one-third of the whole number of 

 measurements, viz : .155, .121, .067, .056, .055, .054, .046, .044, .021, .019, 

 .018, .016, .016, .015, .012, .011. The mean variability of the forty-nine 

 measurements is .017. These facts may have an important bearing upon 

 many questions of radiodynamic probability, especially in regard to the 

 adjustment of commensurable and incommensurable tendencies. 



233. Pi-essure. 

 The experiments of Tresca and Spring, together with those of Crookes, 

 Pictet and Cailletet, show that it is impossible to fix any boundaries be- 

 tween any two of the adjacent states of matter, sethereal, gaseous, liquid, 

 solid, crystalline. J. and P. Curie (Comptes renclus, Ixxxxi, Ixxxxii) con- 

 firm Faraday's hypothesis that magnetized and dielectric bodies should 

 tend to contract in the direction of the lines of force and to dilate at right 

 angles to those lines, a tendency wiiich, as I have shown,* is propagated 

 with the velocity of light. They suppose that between the opposed faces 

 of two contiguous layers of molecules there is a constant difference of ten- 

 sion, involving a condensation of electricity which depends on the dis- 

 tance between the two layers. By experiments with tourmaline and 

 hemihedral crystals with inclined ftices they are led to attach primary im- 

 portance to the form of the molecules, the extremity which corresponds 

 with the most acute solid angles being always negative on dilatation and 

 positive on contraction. They deduce the following laws : 



1. The two extremities of a tourmaline crystal develop quantities of 

 electricity under pressure which are equal, but of opposite kind. 



2. The quantity developed by a given increase of pressure is equal to 

 that which is developed by an equal diminution of pressure, but of oppo- 

 site kind. 



3. This qviantity is proportional to the variation of pressure, is inde- 

 pendent of the length of the crystal, and for the same variation of pressure 

 per unit of surface is proportional to the surface. 



All of these results have an important bearing upon the old maxim that 

 "nothing can act except where it is," and on Newton's consequent belief 

 that the phenomena of gravitation can be more satisfectorily explained b^^ 

 jBthereal pressure than by attracting pulls. They may also help to ex- 

 plain the formation and sublimation of heavy metallic elements, by the 

 immense pressures to which the interior of condensing nebuUu are sub- 

 jected. Many of the aggregating and dissociative tendencies of "sub- 

 sidence," of which my planetary harmonies have given abundant evi- 

 dence, may be exemplified chemically as well as cosmically. 



234. Test of Harmonic Probability. 

 I have endeavored, in my various physical papers, to collect facts, 

 through the guidance of well-known laws, and to account for them by a 

 * See citations in Note 200. 



