034 



described several years ago'; may lie used for this purpose. In tliis 

 way il will not only be possible to determine the heat of' transfor- 

 mation of the moditicalions, but also to study tiie equilibrium between 

 the different foiins. Several interesting problems may find their solu- 

 tion in this way. I have carried out some preliminary experiments in 

 this direction (with cadmium) in collaboration with Mr. W. D. 

 Helderman. 



8. The same may be said if w^e consider the numerous alloys 

 which have an industrial as well as a scientific interest. 



The melting point curves have to be revised, taking into account 

 the allotropy of the components. Quite recently the important part 

 played by the previous thermal history of alloys has lieen discovered. 

 Dippel') has proved that the specific heat of certain alloys is different 

 according as they are chilled or cooled slowly. 



In explaining this fact, Dippel has not been able to take into 

 account the allotropy of the components of the alloys he experi- 

 mented with, as our papers on this subject could not at that time 

 be known to him. 



9. I hope to report shortly on the problems which have been 

 indicated here. We will then discu.ss also several phenomena which 

 are observed in industry, the corrosion of metals in contact with 

 water, rusting of iron, the decay of aluminium objects etc. 



Utrecht. December i9J3. van 't WoYY-Laboratonj. 



Anatomy. — ''On pteric suture.^ and pl.'ric bones in the human 

 skull". By Prof. A. J. P. v. d. Bkoek. (Communicated l)y 

 Prof. L. BoLK). 



It is w^ell known that the pteric region of the skull shows different 

 relations in form and extension of the adjacent sutures as well as 

 in the existence of separate bones, the so called pteric bones, ossa 

 epipterica. 



In most of the human skulls the parietal and the ala magna of 

 the sphenoid touch in a more or less extensive spheno-parietal suture. 



In some skulls the frontal is reached by the temporal bone, then 

 a fronto-temporal suture is formed. In this case we speak of a 

 processus frontalis ossis temporalis. 



The configuration of the pteric region can be influenced by the 

 number, foi-m, extension and situation of the pteric bones. 



i; Zeitschr. f. pliysik. Chem. 30, G23 (1899). 

 '-) Anu. d. Physik 42, 889 (1913). 



