220 Johnston and Adams — High Pressures on the 



Table III. Eelative Values 1 of the Elastic Constants of Metals. 



Metals 







Tensile 







Elastic 



Eigidity 



in order 



Compress- 

 ibility 



Hard- 

 ness 



strength 



Elastic Limit 



(Young's) 

 Modulus 



Modulus 



as in 









lower 1 upper 







Table II 



(a) 



(6) 



(o) 



(d) 



w 



(/) 



(9) 



(h) 



(i) 



K 



31-5 



0'5 



















Na 



15*4 



0'4 



















Pb 



2-2 



1-5 



2-0 



21 



0-3 



25 



102 



17 



5 



0-80 



Sn 



1-7 



1*8 



2-1 



36 



4 



34 



55 



34 



16 



1-50 



Bi 



2'8 



2'5 



















32 



12 





Cd 



1-9 



2 





48 







28 



109 



71 



17 



2-31 



A\ 



13 



2-9 













283 



600 



70 



29 



255 



Zn 



1-5 



2-5 



13 







10 



125 



770 



78 



31 





Ag 



0-84 



2-1 



22 



272 



12 



_ - - 



_ _ . _ 



70 



39 



2-67 



Cn 



0-54 



3-0 



25 



316 



12 



203 



2780 



108 



42 



4-37 



Pd 



0-38 



4-8 











27 



. 







103 



46 





Pt 



0-21 



4-3 



29 



— 



26 











161 



52 



6-46 



1 It is to be noted that the values given in the table are relative only, and 

 are not always expressed in the same units (e. g., columns c and d, e and/, 

 h and i). 



a. As given by Eichards and collaborators, J. Am. Chem. Soc, xxxi, 

 156, 1909. 



b. According to Eydberg, L.-B.-M. Tabellen, p. 57. 



c. L.-B.-M. Tabellen, p. 53. 



d. Wertheim (1848) quoted by Faust and Tammann. Zs. phys. Chem., 

 lxxv, 118. 1911. 



e. L.-B.-M. Tabellen, p. 53. 



/. As determined by Faust and Tammann, loc. cit. 

 g, h. General mean of the (sometimes very discordant) values given in 

 L.-B.-M. Tabellen, pp. 43-45. 



i. Horton, Phil. Trans. Eoy. Soc. London, A, cciv, 1905. 



with the pressure — assumed to act on the solid alone- 

 required to cause the metal to melt at, or about, the ordinary 

 temperature; and suggests that the "flow" of metals — or 

 indeed every permanent distortion of a crystalline* aggregate — 

 is due to an actual fusion (with subsequent resolidihcation) 

 of some of the particles. 



The validity of this view is supported by a large number of 

 well-known facts, e. g., that any metal requires progressively 

 less effort to cause it to weld — or to forge it — as its tempera- 

 ture is higher; indeed this mode of accounting for "flow" 

 has been employed more or less unconsciously by a large num- 

 ber of people as an approximate explanation of a number of 

 common observations such as the above. It is corroborated by 



*The formula is obviously inapplicable to glasses or other supercooled 

 liquid ; for in such cases Q is zero. 



