254 BULLETIN 109, UNITED STATES NATIONAL MUSEUM. 



the State, were severally proposed in the State legislature, and were 

 either rejected or shown to be unnecessary by the existence and the 

 agency of the survey. 



9. In the prosecution of the regular work of the survey general at- 

 tention has been called to the economic resources of the State. The 

 survej' has been directly instrumental, either in instigating in the first 

 instance or by guiding b}' counsel when once begun, nearly all the in- 

 dustries of the State arising from the rocky substructure. This has 

 been done officially and by private correspondence. The native build- 

 ing stones especially have been compared with those from other 

 States and some of their excellencies have been brought out promi- 

 nently, resulting in a great increase of the use of stone native to Min- 

 nesota. 



10. In 1879 an examination was made of the water used for domestic 

 purposes in the western part of the State, It had been discovered 

 that very many of the common wells were foul, and that seri- 

 ous diseases that frequently terminated fatally were traceable to 

 the use of the water in this condition. So general and widespread 

 was this that serious alarm was felt by parties who were largely in- 

 terested in the settlement and habitability of the prairies, particularly 

 in the valley of the Red River of the North, lest the growing evil 

 should render the country unfit for general agricultural occupancy. 

 But the examination showed that the evil was due, not to any un- 

 wholesomeness inherent in the water, but to the general habit of using 

 white pine for curbing for the wells. In the open air, water, which 

 is naturally alkaline, confined in the impervious clay reservoirs, 

 such as nearly every v^ell was, will act rapidly on any organic 

 matter that comes into contact with it. The pitch of the pine 

 was thus converted into organic acids, giving off hydrogen disul- 

 phide. Infusorial organic germs took up their abode in the foul 

 waters and the natural result of the use of such water inevitably 

 followed. It was at once recommended that the use of wooden 

 curbing be abandoned and that in its place some earthen stone, 

 brick, or iron substance be substituted. This recommendation was 

 widely published, both in Minnesota and the newspapers of Manitoba. 

 The consequence was a rapid decline of the evil. Many Avells which 

 had been abandoned were recurbed with other materials. It was very 

 soon known that pine curbing generated disease, and in a year or so 

 nothing more, or very little, was heard further concerning the sup- 

 posed foul waters of the western prairie portion of the State. The 

 correction of this evil and the removal of the supposed alarm that was 

 felt by some capitalists and by the health officers of the State may be 

 considered one of the most important visible benefits that have re- 

 sulted from the survey. 



