322 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
nothing, in the hope of more favorable conditions being brought about 
by Providence rather than by our own efforts. 
Certain lessons, however, the above recital of experience teaches. 
One of them is, never to throw away anything that contains material 
of any value, even though it may seem to be valueless. The time 
inevitably and invariably comes when, through improved conditions 
or better methods, what was waste to one generation becomes of value 
to another. Most of the filling of the old stopes in the Copper Queen 
mine and in the Old Dominion mine has already been re-treated. In 
the case, therefore, of sulphide ore, which is too lean to handle, it 
should be stored underground rather than exposed to the weather at 
the surface. I am not sure whether we are justified in ballasting our 
railroads with the slags which we are making now, lean as they are. 
One can not see how 0.5 per cent of copper and a little gold and 
silver can possibly be recovered to any advantage, and yet the future 
may reveal secrets which will convert such impossibilities into possi- 
“bilities. The slags from the iron blast furnaces, which were deemed 
valueless a generation ago, are made into hydraulic cement to-day. 
We all recognize the waste that has resulted in the past from wash- 
ing away gold tailings, which often ran several dollars in gold to the 
ton. Had they been impounded, the minerals now, through weather- 
ing, would be in the fittest possible condition for cyaniding, and 
would give up to this process their residual values to within a trifle 
of their contents. The same rule of preservation should be appled 
to the tailings from copper works. The sulphides, no matter how 
small their percentage, slowly decay, and give off their copper as 
soluble sulphate, which can be precipitated on scrap iron at a very 
inconsiderable cost. If the locality be such that these waste materials 
can be stored, care, and some outlay, if necessary, should be expended 
in their preservation. 
There seems, however, to be a fascination in contemplating loss 
rather than saving, and while we can not exaggerate the follies of 
waste, it is not fair to the profession to overlook the efforts that have 
been consistently made within the last three-quarters of a century, 
and are still being made, to eliminate waste. One of the anomalies, 
however, of the problem is that the accused mining and technical 
engineers compose the only section of the public which really appre- 
ciates the cost of waste and tries to save. 
The recovery of heat units in our domestic fireplaces and furnaces 
is far less than the recovery of heat from coal burned under our best 
boilers, when measured as power generated in our steam engines. 
And the waste in our kitchens and at our tables involves a greater 
national loss than the waste in our coal mines. In the one case the 
people at large are making no effort to minimize it, while every tech- 
nical man of repute is putting his best endeavors into devising means 
