THE ECONOMIC IMPORTANCE OF BY-PRODUCTS 81 



that something goes out to replace that which entered, but in a 

 different form with greater value, then why does the horticulturist 

 permit so much waste to be removed from his factory without satis- 

 factory returns. 



Before proceeding with this discu.ssion let us now turn our 

 attention to the definition of a by-product and then see how we can 

 tit into horticulture and make use of our waste products. Let us 

 consider several definitions: First, a by-product is a secondary or 

 additional product. A something that is produced in addition to the 

 principal product. Again we define by-products as those materials 

 which in the cultivation or manufacture of any given commodity 

 remains over and which possess or can be made to possess market 

 value. 



In order to emphasize the importance anc" value of by-products 

 1 wish to briefly review two commercial industries, namely, the arti- 

 flcal gas and slaughtering house industries, in which by-products are 

 the great source of Income and at the same time produce commodities 

 of great value to society. 



Stop and think about artificial gas. This is common and known 

 to all. Not long ago there were only two products utilized from the 

 coal — the gas at one end and coke at the other. Today if it were 

 not for the by-products between these two extremes artificial gas 

 would be almost prohibitive. Why? Because there was too much, 

 waste in the manufacture to continue as prices in other commodities 

 steadily Increased. Only a few years ago the thick black viscid 

 liquid which condenses in the pipes during distillation of the gas from 

 coal was not only waste and useless, but its removal was a positive 

 nuisance and a source of trouble and expense. Today the tar is 

 farther distilled and yields a series of valuable by-products of which 

 I wish to mention a few, such as parafine, naptha, benzol, creosote, 

 anthracene, carbolic acid, napthaline, and pitch. The basic oils of 

 coal tar are still farther utilized and they are the source of our ani- 

 line dyes, and the various hues of which are due to the oxidation of 

 aniline by means of acids. The utlization of these products have 

 brought into being new industries in the manufacture of dyes, perfumes, 

 antiseptics, paving material and fuels. Perfumes, soaps and even 

 confectionary, are now manufactures, which are flavored with what 

 is called oil of bitter almond, but which is extracted from the tar 

 which is the refuse of gas making plants. 



To farther show the importance of by-products I wish now to 

 mention the slaughter house. This can be no better illustrated than 

 Is seen in our great packing houses of the present day. Some one 

 has said that only the squeal of a pig or the blat of a sheep is lost 

 in the plant. Is this not true? Isn't every particle from the carcass 

 cf an animal utilized? It is also conceded that the by-products of 



