160 BULLETIN lOy, UNITED STATES NATIONAL MUSEUM. 



logical interest most conspicuous in importance at that time was 

 salt. Doctor Houghton had already visited the shores of the Upper 

 Peninsula in company with Henry R. Schoolscraft, and must have 

 remarked the indications of mineral wealth in that remote region; 

 hut the salt springs of tlie Lower Peninsula were better known and 

 more accessible. They had been noticed from the earliest settlement 

 of the territory, and the General Government had made numerous 

 reservations of salt spring lands. In the act of June 23, 1836, 72 

 sections of these lands were patented to the State. 



FIRST YEAR OF THE SURVEY, 183 7. 



The general impression prevailed in Michigan that salt w^as des- 

 tined to become an important resource. The State geologist accord- 

 ingly devoted his first efforts to a general study of the facts within 

 reach of ready observation. His first report, of 39 pages,' was dated 

 January 22, 1838, and devoted 21 pages to this subject. 



He found the salines of the State distributed in five groups: 

 1. Those upon the Grand River, near Grand Rapids. 2. Those on 

 Maple River, in Gratiot County. 3. Those on the Tittabawassee, in 

 Midland County. 4. Those of Macomb County. 5. Those on the 

 Saline River in Washtenaw County. It was impossible as yet to 

 know that these groups of springs were supplied from formations 

 of three different ages. As saline indications of importance were 

 known south of a line drawn from Monroe to Grand Rapids, Doctor 

 Houghton gave analyses of 20 samples of brine from as many dif- 

 ferent localities within the peninsula. These were generally located 

 on marshes, circumstanced similarly to the salines of New York, or 

 on the immediate banks of streams subject more or less to overflow. 

 The strongest of yield was from 150 to 400 grains of sodium chloride 

 in 100 cubic inches of brine. As the result of the observations this 

 year. Doctor Houghton advanced the opinion that the brine supplied 

 at the surface at any of the localities examined would prove too 

 weak and too limited in quantity to justify the expectation of remun- 

 erative manufacture. At the same time he announced " a general 

 resemblance between the geology of the valley of the Ohio and that 

 of Michigan," and stated his belief that " the rock formations (pre- 

 sumably the surface rocks) of our saliferous district are somewhat 

 lower in the series than those occurring in the principal salines on 

 the Ohio;" and from this " inferred that the salt-bearing rock would 

 be nearer the surface here" than in Ohio. The similarity of cir- 

 cumstances, as he erroneously conceived, attending the occurrence of 



» House Doeuments, 1838, pp. 276-31G. 



