152 



Creek, Bitter Creek, Eclio Caiiou, Weber River, and west as far as the 

 borders of Utah. The same deposits have been found eighty miles 

 above Fort Laramie. The whole product of the Wyoming coal mines is 

 now estimated to be about 20,000 tons per month. 



The SELF-PUEiFiCATiON OF FviVERS has recently attracted the atten- 

 tion of scientific men in England. The discharge of sewage into rivers 

 in the vicinity of densely populated communities, it has been claimed, 

 is not an evil, because the rivers possess the property of self-purifi- 

 cation in exposure to the action of the atmosphere, and in the precipi- 

 tation of impurities to their bottoms. The clear appearance of water 

 after it bas been polluted, and has flowed for a short distance, is alleged 

 to be proof of purification. But this theory of the unscientific public 

 has been refuted by experiments made by an English commission, ap- 

 pointed for the purpose of testing its truth. The results indicate very 

 closely the eflect which would be produced by the flow of a river or 

 stream containing 10 per cent, of sewage for ninety-six and one hundred 

 and two miles resi)ectively, at a rate per hour of one mile. The percent- 

 age reduction of the organic carbon in the first distance would be G.4, 

 and of organic nitrogen, 28.4. For the latter distance the correspond- 

 ing figures are 25.1 and 33,3. As the temperature during this experi- 

 ment was nearly 70° Fahrenheit, it demonstrates that the oxidation of 

 the animal organic matters in sewage i)roceeds very slowl^'. It was 

 also demonstrated, by another experiment on the rate of oxidation of 

 sewage, that supposing a river polluted with the above proportions of 

 sewage received no further contamination for a distance of one hun- 

 dred and eighty-six miles, it would then lose about G2.3 per cent, of its 

 injurious and clfensive properties. But most streams which are pol- 

 luted by animal or vegetable matter receive the pollution near to the 

 cities and towns which use them ; hence, no stream which supplies cities 

 and towns with water can be regarded as even approximately pure, un- 

 less the emptying into it of all sewage and manufacturing refuse is pro- 

 hibited. 



The nutritive value of milk. — Dr. Oliver C. Wiggin, of Provi 

 deuce, Ehode Island, bears the following testimony to the value of milk : 



The nutritive value of milk, as coni])are(l wirli other kinds of animal food, is not 

 generally appi'eciated. Tiiere is less difference hetweu the ecoaomical value of milk 

 and beefsteak (or eggs or iish) thau is commonly supposed. The quantity of water in 

 a good quality of niiik is 86 per cent., in round steak 75 per cent., in fatter beef 60 per 

 cent., in eggs about 68 per cent. From several analyses, made last winter, I estimated 

 sirloin steak, (reckoning loss from bone,) at 35 cents a pound, as dear as milk at 24 

 cents a quart ; round steak, at 20 cents a pound, as dear as milk at 14 cents a quart ; 

 eggs, at 30 cents a dozen, as dear as milk at 20 cents a quart. Many laborers who pay 

 17 cents for corned beef would consider themselves hardly able to pay 10 cents for 

 milk, when, in fact, they could as well afford to pay 15 cents. Milk is a most whole- 

 some and economical food for either the ricli or i)oor. It ought to be more largely 

 used. If the money expended for Aeal and pork were expended for milk, I doubt not 

 it would be an advantage both to the stomach and pocket, especially during the warm 

 season. Relatively speaking, then, milk at 10 cents, or even 12 cents a quart is the 

 cheapest animal foocl that can be used. Whether farmers can alibrd to produce it 

 cheaper is a matter for them to decide. It is very probable that were they to ask 12 

 cents a very large number of poor people would refrain from its use iVoni mistaken 

 notions of economy, notwithstanding they are excessive meat-eaters. 



Centennial Exhibition. — The Forty-first Congress, at its third 

 session, passed an act "to provide for celebrating the one hundredth 

 anniversary of American Independence, by holding an international 

 exhibition of arts, manufactures, and products of the soil and mine, in 

 the city of Philadelphia, in the year 187G," The act specifies that this 

 exhibition shall be held under the auspices of the Government of the 



