CHEMISTRY AND CONSERVATION 



425 



facts to be investigated often fall un- 

 der more than one heading of the 

 classification, and actually interlock in 

 every conceivable manner. To operate 

 a placer mine, for example, abundant 

 water is needed, while a deep mine re- 

 quires timber for its shafts and levels. 

 In building and occupying a house one 

 covers land, uses lumber, brick, stone, 

 and iron, introduces water supply, and 

 burns fuel. In short, every phase of 

 the conservation question affects the 

 interests of everybody. If the investi- 

 gation of our natural resources is to be 

 made effective, it must be applied to 

 individual industries, and in order to 

 do that another scheme of classification 

 would seem to be necessary. Such a 

 scheme we venture to outline, but very 

 briefly. 



At the outset the problem can be 

 divided into two parts, one relating to 

 sources of energy, the other to material 

 substances. The two are not really 

 separable, but may advantageously be 

 considered separately. 



In the first place, the energy avail- 

 able for industrial uses may be classi- 

 fied under three heads, as follows : 

 First, inexhaustible energy, such as 

 solar radiation, wind power, tidal 

 power, and, with certain limitations, 

 the power furnished by flowing streams. 

 Second, reproducible or renewable en- 

 ergy, like the power supplied by horses 

 and other domestic animals. Wood, 

 regarded as fuel, also falls under this 

 heading, for forests can be artificially 

 grown. Third, the exhaustible energy 

 represented by mineral fuel, like nat- 

 ural gas, petroleum, and coal, which, 

 once used, is gone forever. Under 

 this classification the practical prob- 

 lems are, to economize the exhaustible 

 energy, to encourage the development 

 of renewable energy, and to discover 

 new methods of using the inexhausti- 

 ble energy. 



Exactly the same classification ap- 

 plies to material substances. Some, 

 like sea salt, limestone, and clay 

 are, humanly speaking, inexhaustible. 

 Agricultural and forest products are 

 reproducible, some of them year by 

 year. The metallic ores and such use- 



ful minerals as phosphate rock are, 

 however, exhaustible, and need to be 

 conserved. 



\Yith the aid of this very simple 

 classification it becomes possible to 

 analyze a specific industrial problem in 

 such a manner as to make evident its 

 factors of waste or economy. For ex- 

 ample, sea salt is inexhaustible, and 

 may be extracted by solar evaporation, 

 which is a use of inexhaustible energy. 

 Agricultural products are renewable, 

 and their prodution chiefly requires the 

 renewal energy of men and animals. 

 But the smelting of metallic ores, as 

 now conducted, involves the use of ex- 

 haustible material, both as ore and as 

 fuel. 



In most industries, however, the two 

 sets of considerations are combined. 

 Portland cement, for example, is made 

 from inexhaustible substances, but is 

 burned with exhaustible fuel. The lat- 

 ter factor in the industry, therefore, is 

 the one to be carefully considered, 

 while the first factor is negligible. 

 Taking industry by industry we shall 

 find that this condition of affairs is 

 general, and that each one must be 

 studied by itself with reference to its 

 inexhaustible, reproducible, and ex- 

 haustible elements. In doing this a 

 clear notion can be obtained as to the 

 real needs of a given industry, and 

 our attention can then be concentrated 

 upon those features of it which particu- 

 larly demand economy. We shall be 

 able to locate evils with greater accu- 

 racy ; to diagnose the industrial dis- 

 .eases, so to speak, and then to look in- 

 telligently for remedies. Many of the 

 remedies must be sought for along 

 chemical lines of research, which will 

 develop economical processes of manu- 

 facture, utilize materials that are now 

 wasted, or substitute cheap for costly 

 substances. Cheap and costly, how- 

 ever, are words which need qualifica- 

 tion. A substance or a process which 

 is cheap to-day may be in reality waste- 

 ful with a temporary reduction in price 

 at the cost of some permanent econo- 

 my. For our purposes the two words 

 imply a deeper discrimination than is 

 carried by their ordinary use. Tempo- 



