W. Hallock—The Flow of Solids. 59 



Art. X. — The Flow of Solids: A Note ; by William 

 Hallock. 



The justice of Mr. Spring's* protest against a part of my ori- 

 ginal paper I am glad to admit, as far as it concerns an ill-advised 

 use of terms, and a consequent misrepresentation of his views, 

 of course entirely unintentional. Not realizing that many were 

 not so familiar with Mr. Spring's works as myself, I neglected in 

 the brief paper to give his views, and thus my deductions from 

 his results seemed to represent his own conclusions. 



The object of my original investigationf was a solution of the 

 question whether pressure alone is capable of producing true 

 liquefaction ; many have certainly believed so, or even do believe 

 so, and a few, at least, including myself saw in Mr. Spring's 

 earlier results evidence of such a possibility. I believe that to 

 produce such phenomena, as some recrystallizations, and diffu- 

 sion, an increase in the freedom of motion of the molecule, an 

 increased diffusibility, i. e., the beginning of a liquefaction, is 

 indispensable. Hence I looked upon his results as pointing to a 

 liquefaction by pressure. My own experiments with the same 

 substances and pressures showed the impossibility of liquefying 

 them by pressure and even brought out an enormous increase in 

 the rigidity of beeswax and paraffin under such pressures.^ In 

 concluding I wished only to call attention to the difference 

 between Mr. Spring's residts and my own, but unfortunately a 

 loose and abbreviated quotation caused the misunderstanding, 

 which I wish to explain. 



Since obtaining my own results there seems to me little doubt 

 that many, at least, of Mr. Spring's effects are caused rather by a 

 motion under pressure, a kneading, as it were, and by the regrind- 

 ing. The holders in which his compressions were made were not 

 tight and the most perfect welding§ always took place at the 

 surface of the block, or the corners, or where the material was 

 forced into the cracks, often even while the center, under equal 

 pressure, remained almost unaffected. My holders were tight, 

 allowing no leaking or motion, and the substances showed scarcely 

 a trace of a welding under pressure. I must therefore reiterate 

 that which I wished originally to impress, namely that the 

 majority of Mr. Spring's results are not produced by simple cubic 

 static pressure. 



In the cases of chemical action and the formation of alloys, I 

 believe that the motion under pressure will be found to be the all 

 important factor, perhaps just as stirring assists diffusion to com- 



* W. Spring, this Journal, xxxv, 1888, p. 78, also Bull, de l'Acad. R. Belg., xiv, 

 1887, p. 585. 

 f W. Hallock, this Journal, xxxiv, p. 277, 1887. 



X Compare also Ordnance Dep't Tests of Metals, etc., 1884. Gov't Printing Office. 

 § W. Spring, Bull. d. l'Acad. R. Belg., xlix, p. 352, 1880. Phosplwre amorphe et 



