December 27, 1907] 



SCIENCE 



903 



of greenish aporhyolite occurs. It appears to 

 have been at one time a glassy rock. 



The western Shan-Tung district contains 

 rock formations ranging from the oldest Pre- 

 Cambrian to early llesozoic ( ?), consisting of 

 rocks of nietamorphic, igTieous and sedi- 

 mentary origin. The oldest rocks are gneisses 

 and schists. Embracing biotite-gneiss, biotit- 

 ie-hornblende-gneiss, homblende-gTieiss, and 

 schists of similar composition. With these 

 are associated biotite granites. The lime- 

 stones and shales forming the Sinian system 

 present features of interest in the oolitic con- 

 cretions that have been extensively developed, 

 and have subsequently undergone recrystalliza- 

 tion into aggregates of coarser crystals, and in 

 the conglomeratic character of some of the 

 limestone interformational conglomerates. 

 These sedimentary rocks are described in de- 

 tail. Associated with the Sinian series are 

 basaltic and dacitic porphyries, besides syenitie 

 and quartz-syenite porphyries in dikes and in- 

 truded sheets. The carboniferous strata over- 

 lying the Sinian series are traversed by dil?:es 

 and sheets of various kinds of rocks, and by 

 some extrusive flows of basalt. The com- 

 monest rocks are basalts and syenite-por- 

 phyries, with some dacites and andesites. 

 There is also less commonly gabbro and 

 peridotite. 



In western Chi-Li there is a complex of 

 gneisses, schists, granites and porphyries 

 covering extensive areas. So far as evidence 

 was found, the metamorphic rocks appeared to 

 be mostly of igneous origin; in one instance 

 there was proof of a sedimentary source. This 

 complex is followed by the Ta-yang series of 

 limestones, with shale and quartzite, of Algon- 

 kian age; and by the sedimentary rocks of the 

 Sinian system. 



The Wu-T'ai district consists mostly of 

 metamorphosed Algonkian sediments, some of 

 which are highly altered, while others are but 

 slightly changed, resembling in places Paleo- 

 zoic rocks. The more metamorphosed series 

 called the Wu-T'ai system consists of mica- 

 schists, gneisses, garnet-schists, chlorite- 

 sehists, quartzites, marble, schistose conglom- 

 erates, arkoses, etc. With these are some 

 eruptive rocks, more or less metamorphosed : 



granite, augen-gneiss, hornblende-schists, 

 quartz-porphyries, etc. The less meta- 

 morphosed series, the ITu-T'o system, consists 

 of slates, graywackes, limestones and quartz- 

 ites, with fewer igneous rocks, in dikes, both 

 basic and acid. The district also contains 

 rocks of the Sinian system. 



The rocks of the Ts'in-ling district are 

 mostly sedimentary; either highly meta- 

 morphosed or only slightly altered. There are 

 also large intrusions of granite and occasional 

 dikes of other igneous rocks. The same may 

 be said of the Han Kiver district, the rocks of 

 which are described in considerable detail. 



The Tang-Tzi Gorge district is chiefly sedi- 

 mentary rocks of Paleozoic age, with local ex- 

 posures of Mesozoic and Pre-Cambrian ter- 

 ranes. They are strongly but not intensely 

 folded, and are not notably metamoi-phosed, 

 except the oldest formations. 



The report closes with a resume of litera- 

 ture containing descriptions of the rocks of 

 China, which shows that very little has been 

 done in this direction. Mr. Blackwelder's re- 

 port is a valuable contribution to the petrog- 

 raphy of the region, and it is to be regretted 

 that he was not in a position to pursue his 

 studies more thoroughly and systematically, 

 and that no chemical analysis of the best of his 

 material was undertaken. 



J. P. Iddings 



Annual Reports of the Progress of Chemistry 



for 1906. Issued by the Chemical Society. 



Vol. III. London, Gurney and Jackson. 



1907. Pp. 387. Price $2 net. 



The development of chemistry in many dif- 

 ferent directions is so very rapid that it is 

 impossible for any one to keep informed even 

 with regard to the important work which is 

 published in the various fields. The reports 

 of progress which are published annually, by 

 the London Chemical Society, serve, there- 

 fore, a very useful purpose in bringing to- 

 gether a summary of the really important 

 advances of the science during a given year. 

 The divisions of the present volume are : Gen- 

 eral and Physical Chemistry, by Alexander 

 Findlay; Inorganic Chemistry, by P. P. Bed- 

 son; Organic Chemistry — Aliphatic Division, 



