144 



SCIENCE 



[N. S. Vol. XL. No. 1021 



Equilibrium in the System — Mercurio lodide-Ani- 



lin: J. N. Pearce and E. J. Tky. 



A complete curve representing the conditions of 

 equilibrium between mercuric iodide and anilin has 

 been plotted for temperatures between — 11.48° 

 and 199.9°. The region of stability of the three 

 solids Hgl2-2CeN,H, red mercuric iodide, and yel- 

 low mercuric iodide have been established. Six- 

 teen solubility measurements of mercuric iodide in 

 anilin are given, all in duplicate and mostly in 

 triplicate. A new compound corresponding to the 

 formula CbH,N-HG»I2 has been identified and de- 

 scribed. The compound Hgl2-2C6H,lSr has been 

 made by direct combination of mercuric iodide 

 with anilin. A method for the determination of 

 mercuric iodide as mercuric sulphide in the pres- 

 ence of an easily oxidized organic solvent has been 

 tested. 



The Electrical Conductivity of Solutions on Cer- 

 tain Electrolytes in Organic Solvents: J. N. 

 Peakce. 



Earth Movements and Drainage Lines in Iowa: 



James H. Lees. 



The paper aims to bring together existing knowl- 

 edge concerning drainage conditions in northeast- 

 ern Iowa and to show that the present system is 

 the resultant of uplifts and warpings of the strata 

 at different periods and from various centers. 

 The fact that the streams are flowing far above 

 the bottoms of their valleys is attributed to 

 changes necessitated by glacial action and to low- 

 ering of the land surface. 



Some Evidences of decent Progress in Geology: 



George P. Kat. 



In this paper reference is made to some of the 

 most important geological papers published dur- 

 ing the last ten years and which indicate the lines 

 along which the greatest progress has been and is 

 being made. 

 Siouan Mountains: An lowan Triassio Episode: 



Charles Keyes. 



The true significance of the abrupt cutting off 

 to the northward of the Iowa belted Paleozoies is 

 obscured by the fact that Cretacic sediments over- 

 lie points at which critical evidence might be ex- 

 pected. Lately, deep-well records and other data 

 have disclosed a substructure that is quite re- 

 markable. It is now known that over the high arch 

 extending from Lake Superior southwestward into 

 South Dakota the Cambric, Ordovicic, Siluric, De- 

 vonie and Carbonic formations were spread out. 

 The uprising appears to have taken place in Tri- 



assic times; and in Comanchan time the entire 

 mountainous ridge, 5,000 feet high, was planed off 

 and completely base-leveled. Upon this pene- 

 plained surface the Mid Cretacic sediments were 

 laid down. This period of base-leveling also ap- 

 pears to fix the date of peneplain forming the 

 Lake Superior highlands. 



Serial Unit m Stratigraphic Classification: 



Charles Keyes. 



The recent movement to test the validity of each 

 formational unit by criteria other than that of the 

 contained fossils has led to important and rather 

 unexpected advancements in stratigraphical classi- 

 fication. The fact that this movement is also in 

 the direction of simplicity argues for its still wider 

 adoption. In Iowa, Illinois and Missouri the 

 Early Carbonic succession is a good illustration of 

 the point under consideration. By emphasizing 

 the paleogeographical and diastrophic factors and 

 adapting, so far as is possible, the nomenclature 

 already in use the various terranes may be 

 grouped into three grand divisions having serial 

 rank. These groups are the Waverleyan series, the 

 Mississippiau series and the Tennesseean series. 

 At divers times other names have been proposed, 

 that might be used but for the fact that they are 

 preoccupied. The division is essentially the same 

 as that first suggested by Owen more than sixty 

 years ago. 



Stratigraphic Position of Our Oldest Socles: 



Charles Keyes. 



Although the Sioux quartzite, which crops out 

 where the three states of Iowa, Minnesota and 

 South Dakota meet, has been long known and re- 

 peatedly described, little has ever been learned of 

 its tectonic relationships or of its real position in 

 the general geologic column. The Corson diabases, 

 the Hull porphyries and the Tipton sandstones 

 now appear to belong to the Keewenawan series 

 of the Proterozoic era. The Split-Rock slates, the 

 Sioux quartzite and the Jasper conglomerates are 

 Animikean in age. The Archeozoic is not repre- 

 sented. The gneisses of Le Mars and the schists 

 of Sioux City form a part of the Azoic complex. 



On Precious Stones in the Glacial Drift: Garrett 



A. MUILENBURG. 



A New Section of the Railway Cut near Graf, 



Iowa: A. O. Thomas. 



This artificial section exposed along the Chicago 

 Great Western railway in Dubuque county has been 

 made famous by the writings of James and of 

 Calvin. It has recently been cut back for quite a 



