GEOLOGICAL AND NATURAL HISTORY SURVEYS. 269 



features of tlie deposits that form its substrata. A summary report 

 of this important exploration was given by him at the Indianapolis 

 meeting of the American Association for the Advancement of Science 

 and was published in the volume of proceedings for 1871 (p. 252). 

 The outcome of these observations is there summarily stated to have 

 been that " the true river deposits " of any considerable thickness 

 are mostly confined to narrow strips of land lying on both sides of 

 the Mississippi and of the bayous and creeks and to ancient channels 

 since filled up ; while a large proportion of the superficial area of the 

 bottom, including some of the most fertile lands, is derived from 

 the clays of older formations into which these beds have been ex- 

 cavated. The equivalence of this older clay formation with that of 

 the Port Hudson profile, already suggested, was thus verified. 



Returning to Oxford early in December, Doctor Smith carried on 

 the chemical work until the end of May, 1871, when he took the field 

 again in order to trace across the State the " siliceous Claiborne " 

 belt above referred to. His route lay from Leake County southeast- 

 ward to the Alabama line, along the northern contact of the prob- 

 lematic " Red Hills " and yellow sandstones with the lignitic forma- 

 tion; then westward again in the more southerly portion of the belt, 

 to the border of the Yazoo bottom (the "Mississippi bluff"). In 

 this trip he traced the connection and established the equivalence of 

 the ferruginous formation as a local feature, with the sandstones of 

 Neshoba and Newton Counties, which again connect unequivocally 

 with the characteristic " buhrstones " of Lauderdale. 



In September, 1871, Doctor Smith resigned the assistantship to 

 take the chair of geology and mineralogy in the University of Ala- 

 bama, with which, through his efforts, the office of State geologist of 

 the latter State was afterwards connected. 



His successor in the assistantship of the Mississippi survey was 

 Mr. R. H. Loughridge, of Texas, who had for some time previously 

 acted as Hilgard's assistant in the chemical laboratory and subse- 

 quently as instructor in general chemistry. Mr. Loughridge prose- 

 cuted the chemical work of the survey during a part of the year 

 1872, while Doctor Hilgard was preparing for the elaboration of 

 another report covering the work done since the publication of tlie 

 report of 18G0, when, by arbitrary ruling of the State auditor of 

 public accounts, the survey appropriation was withheld, and thus 

 in the autumn of 1872 the work was preemptorily stopped and has 

 not been revived since, although the act of 1860 has never been 

 legally rescinded. No provision for the publication of the results 

 has ever been made by the State. The records and collections of 

 the survey remained in custody of the TTniversity of Mi?;sissippi, and 

 were left bv Doctor Hilgard fullv labeled as to localitv and time of 



