DESTRUCTIVENESS OF MAN. an. 
only from slow development, from possible, unknown cosmical 
causes, or from geological action. 
But man, the domestic animals that serve him, the field and 
garden plants the products of which supply him with food and 
clothing, cannot subsist and rise to the full development of 
their higher properties, unless brute and unconscious nature be 
effectually combated, and, in a great degree, vanquished by 
human art. Hence, a certain measure of transformation of 
terrestrial surface, of suppression of natural, and stimulation of 
artificially modified productivity becomes necessary. This 
measure man has unfortunately exceeded. He has felled the 
forests whose network of fibrous roots bound the mould to the 
rocky skeleton of the earth; but had he allowed here and there 
a belt of woodland to reproduce itself by spontaneous propaga- 
tion, most of the mischiefs which his reckless destruction of the 
natural protection of the soil has occasioned would have been 
useless incumbrance, but it is now valued at ten or twelve dollars per ton for 
the cotton fibre which adheres to it, for the oil extracted from it, and for the 
feed which the refuse furnishes to cattle. The oil—which may be described 
as neutral—is used very largely for mixing with other oils, many of which 
bear a large proportion of it without injury to their special properties. 
There are still, however, cases of enormous waste in many mineral and me- 
chanical industries. ' Thus, while in many European countries common salt is 
a government monopoly, and consequently so dear that the poor do not use as 
much of it as health requires, in others, as in Transylvania, where it is quar- 
ried like stone, the large blocks only are saved, the fragments, to the amount 
of millions of hundred weights, being thrown away.—Bonar, TJransylvania, 
p. 455, 6. 
One of the most interesting and important branches of economy at the 
present day is the recovery of agents such as ammonia and others which had 
been utilized in chemical manufactures, and re-employing them indefinitely 
aiterwards in repeating the same process. 
Among the supplemental exhibitions which will be formed in connection 
with the Vienna Universal Exhibition is to be one showing what steps have 
been taken since 1851 (the date of the first London Exhibition) in the utiliza- 
tion of substances previously regarded as waste. On the one hand will be 
shown the waste products in allthe industrial processes included in the forth- 
coming Exhibition; on the other hand, the useful products which have been 
obtained from such wastes since 1851. This is intended to serve as an incen- 
tive to further researches in the same important direction, 
