person unaccustomed to the process is struck with astonishment, amounting almost to terror, as the muddy mass sweeps onward, bearing in its course the great rolling bowlders, which add their din to the roar of the water, the whole being precipitated down a series of falls, at each of which it is caught up again by new sluices of timber, lined like the first, and so onward and downward many hundreds of feet until the level of the river is reached, at a distance of about a half mile or more from the mouth of the first tunnel.

At each of these new falls of 25 to 50 feet the process of comminution begun in the first shaft is carried on, and a fresh portion of gold obtained.  Rude as this plan of saving gold appears to be, more gold is procured by it than by any other method of washing yet devised for this process of work, and the economical advantages obtained by it cannot be surpassed, as it would be impossible to handle such vast quantities of material in any other way, and we can compare the cost of washing and handling a cubic yard of auriferous gravel by it as follows: 

Dollars. 
By manual labor with the pan              15.00
"       "   with rocker                3.75
"       "   with the long tom           .75
By the hydraulic process                    .15

But this process, even if effective or profitable as a mining operation, may be prejudicial to the interests of the general public, if conducted on a large scale, as the vast quantity of material which it so suddenly removes is merely shifted into the shallows beneath, to be redistributed by every freshet to points lower and lower down until it reaches the sea-coast, creating bars at the mouths of rivers in its course, and changing the hydrography of harbors—­as it has done with the Bay of San Francisco by its silt.

The hills behind, torn up and washed by the gold miner, are abandoned as desolate and irredeemable; and the costly canals, constructed with peculiar conveniences for mining purposes, eventually fall into disuse from being too expensive to maintain or alter for general agricultural uses.—­Journal of Science.

* * * * *

THE TREATMENT OF CHOLERA.

From the host of remedies and suggestions that are now deluging the European medical press, we select the following from Dr. Henry A. Rawlins, in the London Med.  Times, July 12. 1884: 

The man suffering from cholera has been suddenly deprived by diarrhoea of an enormous quantity of the fluid part of his blood.  This loss is one of simple transudation, increasing as the powers of life decrease.  This sudden loss produces intense prostration, and renders the heart powerless to perfect the circulation.  The body, thus deprived of oxygen, speedily runs into decomposition, even before life is extinct.  Have we any agent by which we can collect and press forward