270 SPARKS FROM A GEOLOGIST'S HAMMER. 



ascent of brine from deep underlying formations. It 

 raised the query how brine, which is heavier than water, 

 should be made to ascend several hundred feet through 

 fissures accessible to shallower fresh waters, even if such 

 fissures existed, arid showed that of necessity the undi- 

 luted brine from any deep-seated formation must be 

 pumped up; and that if salt water overflows at an arte- 

 sian boring, it results simply from a head of fresh water 

 mingled \yith some accidental supply of brine. It showed 

 that the marginal salt springs of the state are simply 

 drippings from the salt-bearing formations, prompted by 

 the descent of fresh waters into them, and greatly diluted 

 by rains falling near the locations of the springs. It 

 showed that the salt springs of Michigan, which had been 

 the object of so much exploration, legislation and expendi- 

 ture, possess no importance except as " licks " for wild 

 animals, and that the seventy-two sections of " salt spring 

 lands" patented to the state never possessed any value 

 above that of ordinary agricultural lands.* 



In July 1862, in consequence of some new facts com- 

 municated by Dr. Lathrop, I revisited the Saginaw region, 

 and studied all the new developments. Dr. Lathrop sup- 

 plied, in addition to previous information, specimens of 

 chips from the "Orange County Company's" well, and Mr. 

 Sutherland furnished borings from the " Ann Arbor and 

 Saginaw Company's" well. I had also the opportunity 

 of consulting a complete register of the " Carrollton Mill 

 Salt Company's" well, and got some information from 

 Davis & Co., of Zilwaukee, and other facts concerning the 



* Most of these points were brought out in the Report submitted December 

 31, I860, and printed in 1861. See especially pp. 165-6. 



