927 
In the second paper') we called attention to the fact that this 
result was corroborated by Le Vwrrigr’s experiments, who found as 
long as twenty two years ago, that the specific heat of Pb, Zn, Al, 
Ag, and Cu is a function of the previous thermal treatment of 
these metals. 
2. Although the values given by Lr Verrier are mentioned in 
different physico-chemical tables, only small attention has been given 
to them. In those cases where this has been done, they have generally 
been considered as less accurate. Such is for example the.case with 
SCHÜBEL *), who says in a paper published recently : 
“Nicht mit aufgenommen sind die Beobachtungen von Lr VeRRIER, 
Al, Cu, Ag, Zn; Le Verrter findet Unstetigkeiten in seinen Kurven 
der mittleren spezifischen Wärme als Funktion der Temperatur, 
welche nicht wieder beobachtet wurden, so dass die von ihm 
gefundenen Werte für die mittlere spezifische Wärme héchst unwahr- 
scheinlich geworden sind.” 
3. However, it may be pointed out that others would have been 
able to find the same results as Le Verrimr only if they had inves- 
tigated specimina of the same metal possessing different thermal histo- 
ries, as Lr Verrier did. 
We shall see below what discrepancies occur if this precaution 
is omitted. It will be proved then also that Le Verrier has been 
up to the present the only investigator who has paid sufficient 
attention to this point. 
4. The fact that different authors have found (at the same tem- 
perature) for a certain metal very different values of the specific 
heat, must partly be attributed to their omitting to take into account 
the previous heat treatment of the metal experimented with. From 
the enormous material found in the literature, we only quote here 
the values for bismuth found at 18° by L. Lorenz *) to be 0,0308, 
whilst JAEGER and DriessrLHORST *) give 0,0292. The difference is 
3 percent. But also differences as high as 13 percent occur, as might 
be seen from the paper of ScHüBEL, mentioned above. 
5. That these facts recently have attracted notice on the part of 
1) Proc. 17, 200 (1914). 
2) Zeitschr. f. anorg. Chemie 87, 81 °(1914). 
3) Wied. Ann. 13, 437 (1881). 
4) Abhandl. der Physik, Techn, Reichsanstalt 3, 269 (1900). 
