abstracts: physical chemistry 89 



entific point of view, but also from the bearing of the facts thus dis- 

 covered upon a number of geological inquiries and upon the problem of 

 the nature of portland-cement clinker. Many papers on this general 

 topic have, of course, already been published, but the work recorded is 

 in the main fragmentary and of little avail in settling the large general 

 questions involved. The present investigation aims to treat the sys- 

 tem rather completely, to ascertain the equilibrium relations in the sys- 

 tem. To this end all the possible compounds which are found in dry 

 melts of the three oxides CaO, AI2O3, Si02 have been determined, es- 

 pecially those which are stable at the liquidus; this involves measure- 

 ments of the respective melting-points or dissociation temperatures, 

 and the determination of the invariant points, boundary curves (mono- 

 variant systems) , and fields of stabilit}^ (divariant systems) of the various 

 compounds. 



This paper contains a summary record of the work performed; it is 

 the first thoroughgoing attempt, so far as known, to determine all the 

 compounds, both binary and ternary, of CaO, AI2O3, SiOo, and the mu- 

 tual relations of these compounds, many of which have, of course, previ- 

 ously been made synthetically by others. The data obtained are made 

 use of in a discussion of the nature and constitution of portland-cement 

 clinker and of the formation of certain natural minerals from the magma. 



Three papers dealing with this system have already appeared from the 

 Geophysical Laboratory. The first two dealt with the binary systems,^ 

 while in the third- provisional locations were assigned to ternary quin- 

 tuple points and boundarj^ curves and the new relations applied in a 

 discussion of the constitution of portland-cement clinker. In the pres- 

 ent paper a more exact location is given for the eutectics, quintuple 

 pomts, and boundary curves, together with the corresponding tempera- 

 tures. Because of the large amount of data it has not been possible to 

 give in a paper of this nature more than the mean values obtained from 

 a large number of determinations of the various points. But complete 

 tables of data and a much more complete discussion of methods and 

 apparatus and of the results obtained will be given in a later mono- 

 graph. F. E. W. 



1 The lime-silica scries of minerals. A. L. Day, E. S. Shepherd, and F. E. 

 Wright. Am. Jour. Sci. (4), 22: 265. 1906. The binary systems of alumina, with 

 silica, lime, and magnesie. E. S. Shepherd, G. A. Rankin, and F. E. Wright. 

 Amer. Jour. Sci. (4), 28: 293. 1909. 



- Preliminary report on the ternary system CaO-AUOj-SiOo. A study of the 

 constitution of portland-cement clinker. E. S. Shepherd, G. A. Rankin, and F. 

 E. Wright. Jour. Ind. Eng. Chem., 3: 1-43. 1911. 



