380 Professor Hausmann on Metallurgical Phenomena 



once inevitable, that, in the composition of the original nucleus 

 of the earth, iron increases from the exterior to the interior. The 

 same fact would then hold good also of other metals which are 

 found most abundant in veins, as we are authorized to consider 

 the largest portion of them as of later formation than the moun- 

 tain-masses in which they exist. Meanwhile, the above obser- 

 vation would harmonize too with the assumption, that, while the 

 mass of the nucleus of the earth subjected to the process of oxi- 

 dation had originally been of a comparatively simple nature, the 

 more easily oxidizable ingredients were transformed in the first 

 instance chiefly into oxidized substances, and that the process of 

 oxidation operated more strongly upon the substances less nearly 

 allied to oxygen, in proportion to the advancement of the pro- 

 cess. At all events, whether we decide for the one explanation 

 or the other, an objection against the theory of Davy is thereby 

 obviated, viz. that, if the mass of the nucleus of the earth were 

 chiefly composed of the bases of the earths and alkalies, it would 

 have a much less specific gravity than any investigations into its 

 medium density have proved. 



(To be concluded in next Number. j 



On the Cause of the Temperature of Hot avd Thermal Springs ; 

 and on the bearings of this subject, as connected with the ge- 

 neral question regarding the Internal Temperature of the 

 Earth. By Professor Gustav Bischoff of Bonn. Commu- 

 nicated by the Author. (Continued from Vol. XX. p. 

 376.* 

 Chap. VII. — Do the rains and other meteoric waters came greater va- 

 riations in the temperature of the soil than in that of the air. 

 The winter rains between the tropics being supposed to have 

 the effect of cooling the springs in those regions, I made some 

 experiments in order to ascertain, to what extent such a depres- 

 sion might possibly proceed. 



The mean temperature at Cumana, according to Don Faustin 



• Owing to the loss of Professor Bischoff's manuscript somewhere between 

 Bonn and London, a considerable time elapsed before a fresh copy could 

 be obtained from the author, a circumstance which explains the long interval 

 between the publication of the present and the former part of this important 

 memoir. 



