126 BULLETIN 10&, UNITED STATES NATIONAL MUSEUM. 



The usual reports of the finding of lead and copper were then 

 alluded to ; then, briefly, the limestones, more or less clay and ochres 

 occurring at various points, notably under the saliferous soils on 

 Lake Bistineau. 



Gypsum was mentioned as occurring in the salines of north 

 Louisiana; also soda springs, from which, during the war, baking 

 soda was boiled by the inhabitants. 



Lignite and peat were also discussed, and finally petroleum, which 

 at that time had excited high expectations in some portions of the 

 State. 



In November, 1865, Prof. Richard Owen, then acting as colonel 

 of an Indiana regiment stationed at New Iberia, cursorily examined 

 the geological features of Petite Anse, with a view to determining 

 the age of the rock-salt deposits there occurring. His conclusions 

 were substantially to the effect that the theory of a volcanic origin 

 of the islands was whoU}' unfounded, and that the salt bed was prob- 

 ably the result of evaporation of modern sea Avater forming the la- 

 goons behind the protecting ridges and filled duriiig periods of ex- 

 ceptionally high tides. 



In 1866 two points in the geology of Louisiana were referred to 

 Prof. E. W. Ililgard for investigation. One was the determination 

 and discussion of the fossil material taken from a well bored at New 

 Orleans in 1866 at a depth of 230 feet, specimens of v/hich had been 

 collected by a committee of the New Orleans Academy of Sciences 

 and placed at the disposal of the chief of engineers, A. A. Humph- 

 reys. The second was an examination of tlie geological position and 

 relations of the rock-salt deposits of Petite Anse, above referred to. 

 This latter proposition was made by Prof. Joseph Henry, secretary 

 of the Smithsonian Institution, with an offer to defray the neces- 

 sary traveling expenses out of the Smithsonian fund. Other duties 

 compelled Professor Hilgard to defer the examination of this deposit 

 to the succeeding year, but he made a preliminary examination of 

 the fossils from the New Orleans well, which were found in the main 

 to agree with the marine species then living in the Gulf. 



In November, 1867, in pursuance of a renewed offer of assist- 

 ance from the Smithsonian Institution, Professor Hilgard undertook 

 the investigation of the geological relations of the Petite Anse salt 

 deposit, the solution of which involved a general examination of the 

 ancient and modern deposits, as well as the delta formations of the 

 Mississippi Valley and adjacent coasts. Beyond the fact that the 

 salt deposit underlaid and was, therefore, anterior to the Lafayette 

 formations, and was not an accidental lagoon deposit, as had been 

 previously conjectured by Professor Owen, no clew to its real age 

 could be found. Professor Hilgard was, however, unwilling to let 



