36 DESTRUCTIVENESS OF MAN. 
The earth was not, in its natural condition, completely 
adapted to the use of man, but only to the sustenance of wild 
animals and wild vegetation. These live, multiply their kind 
in just proportion, and attain their perfect measure of strength 
and beauty, without producing or requiring any important 
change in the natural arrangements of surface, or in each other’s 
spontaneous tendencies, except such mutual repression of 
excessive increase as may prevent the extirpation of one species 
by the encroachments of another. In short, without man, lower 
animal and spontaneous vegetable life would have been prac- 
tically constant in type, distribution, and proportion, and the 
physical geography of the earth would have remained undis- 
turbed for indefinite periods, and been subject to revolution 
world. The utilization—or, as the Germans more happily call it, the Verwer- 
thung, the Jeworthing—of waste from metallurgical, chemical, and manufac- 
turing establishments, is among the most important results of the application 
of science to industrial purposes. The incidental products from the laborato- 
ries of manufacturing chemists often become more valuable than those for the 
preparation of which they were erected. The slags from silver refineries, and 
even from smelting houses of the coarser metals, have not unfrequently 
yielded to a second operator a better return than the first had derived from 
dealing with the natural ore; and the saving of lead carried off in the smoke 
of furnaces has, of itself, given a large profit on the capital invested in the 
works. According to Ures Dictionary of Aris, see yol. ii., p. 832, an Eng- 
lish miner has constructed flues five miles in length for the condensation 
of the smoke from his lead-works, and makes thereby an annual saving of 
metal to the value of ten thousand pounds sterling. A few years ago, an 
officer of an American mint was charged with embezzling gold committed to 
him for coinage. He insisted, in his defence, that much of the metal was 
volatilized and lost in refining and melting, and upon scraping the chimneys 
of the melting furnaces and the roofs of the adjacent houses, gold enough 
was found in the soot to account for no small part of the deficiency. 
The substitution of expensive machinery for manual labor, even in agricul- 
ture—not to speak of older and more familiar applications—besides being 
highly remunerative, has better secured the harvests, and it is computed that 
the 230,000 threshing machines used in the United States in 1870 obtained five 
per cent. more grain from the sheaves which passed through them than could 
have been secured by the use of the flail. 
The cotton growing States in America produce annually nearly three million 
tons of cotton seed. This, until very recently, has been thrown away as a 
