442 POPULAR SCIENCE MONTHLY. 



In addition to our annual supply of 4,000,000 tons of paper stock, 

 we depend upon the forests for our supply of acetic acid, methyl 

 alcohol and acetone. In countries where there is not the exorbitant 

 tax upon fermented mash that exists in the United States there would 

 seem to be an opening for a process for the production of acetic acid 

 from alcohol in a more concentrated form than can be produced 

 through the aid of my co derma, aceti. It would, it is true, in the end 

 depend upon the supply of fermentative material; but there are being 

 wasted every year in the semi-tropical countries many thousand tons of 

 crude molasses that could thus serve an economic end. For many 

 uses acetic acid may be displaced by formic acid, a compound which 

 admits of synthesis from carbon and water. The farther this sub- 

 stitution is carried the more acetic acid will be available for the manu- 

 facture of acetone and other compounds where the acetyl group is a 

 necessity. 



Concurrent with the disappearing forests is the increasing scarcity 

 of vegetable tanning material. Hemlock and oak bark, sumac and 

 chestnut wood are still the most important sources of tannins, although 

 quebracho from South America and canaigre from Mexico and Texas 

 are daily playing a more important part. The introduction of chrome 

 tannage for upper leathers had a marked influence upon this industry 

 inasmuch as it furnished a cheap substitute for those finer tanning 

 materials which were constantly increasing in price. A mineral tan- 

 nage for heavy hides, along the lines so successfully followed for upper 

 leather has, however, not been developed ; the product lacks the rigidity 

 and firmness combined with the flexibility which is characteristic of 

 oak or hemlock tanned leather. There must exist methods for supply- 

 ing to the hide, materials having an action analogous to these vegetable 

 tannins; it remains but to seek them out in order that a new and 

 profitable industry may be established. 



It is thus seen that technical chemistry can do much for the con- 

 servation of our forests; along many lines the time for action has 

 already come. 



When the consumption of a given article is in excess of its supply 

 the market price must rise. In accordance with this law we have 

 seen the price of crude India rubber more than double in the last few 

 years. The consumer of the finished article must pay this advance or 

 accept an inferior grade of goods. Generally he does both. 



The tropical forests of Africa and South America still contain 

 untold quantities of India rubber; but so does sea water contain gold. 

 For manufacturing purposes both might as well not exist. The only 

 human beings that can live under the conditions obtaining in these 

 tropical jungles are the natives; but the distance to which the natives 

 can transport the rubber is comparatively limited. Although rubber- 



