the highlands as fast or faster than the seed crop exhausts it.  Sixty bushels of wheat or two bales of cotton may be harvested from an acre of bottom lands.  So vast in proportions is the yearly crop of food stuffs that more than three hundred thousand freight cars and about two thousand vessels are required to move the crop from farm to market.  One hundred and twenty-five thousand miles of railway, fifteen thousand miles of navigable water, exclusive of the Great Lakes, and several thousand miles of canals are insufficient to transport this enormous production; thousands of miles of railway are therefore yearly built in order to keep pace with the growth of population and the settlement of new lands.  To the natural resources of the soil add the enormous mineral wealth hidden but a few feet below the surface, and wonder grows to amazement.  Coal fields surpassing in extent all the remaining fields in the world; iron ore sufficient to stock the world with iron and steel for the next thousand years; copper of the finest quality; zinc, lead, salt, building stone and timber, all in quantities sufficient for a population a hundred times as great.  Is it strange that wise economists point to this territory and say, “Behold the future empire of the world”?  Where in the wide world is another valley in which climate, latitude and nature have been so liberal?

It is only a few years since the Indian and the bison divided between them the sole possession of this region.  What a change hath the hand of destiny wrought!  What a revelation, had some unseen hand lifted the curtain that separated the past from the future!  Iron, steam and electricity have in them more of mysterious power than ever oriental fancy accredited to the genii of the lamp, and the future of the basin of the Mississippi will be a greater wonder than the past.

The feast of La Salle was the death warrant of the Indian, and the Aryan has crowded out the Indian, just as the latter evicted the mound builder—­just as the mound builder overcame the people whose monuments of burned brick and cut stone now lie fifty feet below the surface.  Only a few centuries have gone by since these happenings; can we number the years hence when rapacious hordes from another land shall drive out the effete descendants of the now sturdy Aryan?

(To be continued.)

* * * * *

FREEZING MIXTURES.

The following selection of mixtures causing various degrees of cold, the starting point of the cooling being indicated in the first column, will probably serve many purposes.  It should be stated that the amount of depression in temperature will practically be the same, even if the temperature to start from is higher.  Of course in the case of snow it cannot be higher than 0 deg.  C. (32 deg.  F.) But in some cases it is necessary to start at a temperature below 0 deg.  C. For instance, the temperature of -49 deg.  C. may be reached by mixing 1 part of snow with 1/2 part of dilute nitric acid.  But then the snow must have the temperature -23 deg.  C. If it were only at 0 deg.  C., the depression would be only to about -26 deg.  C.: