How Far Can We Go in Chemurgy?

Wheeler McMillen.

The achievements reported in these pages show that unsuspected uses for agricultural raw materials have been created by scientific inquiry. Profitable commercial utilization has been established for farm residues formerly of little or no market value. Entirely new crops have gained a foothold, and some have become important factors in total production. How far can progress go in the fields of chemurgy? Can research profitably be pursued further?

The answer seems completely clear. The place to catch fish is where fish are being caught. Where so much already has been accomplished there must be much more to be done.

At the risk of restating well-known fundamentals, it may be well here to recall the new conditions that have made these advances in chemurgy possible. Agriculture from its primitive beginnings has been an individualistic, unorganized, empirical business. Gains in knowledge came mostly from scattered observations. Little, or indeed almost nothing, of true science existed in agriculture until the latter part of the past century.

During the 1890's organic chemistry began to be important, and Mendel's law, the basic principle of plant genetics, became known. The early part of this century saw the rising application of power to agriculture. These three relatively recent developments in chemistry, genetics, and engineering have made chemurgy possible. They have provided a wholly new set of tools for moving agriculture forward in new directions. Organic chemistry and related sciences enable industry to extract values from plant substances that always before had been inaccessible or were useful only in crude forms. The science of genetics permits plant breeders to improve and intensify the characteristics of a plant species which may prove to be commercially desirable. The developments in power and machinery meanwhile have multiplied human and animal muscle so that materials can be moved, lifted, ground, and processed to degrees that never before were possible.

All those advances have come about within a generation or so. They are so recent that up to now, even with the resources of industry, individuals, and Government, there has been little time to apply them extensively. Only a few of the more obvious opportunities have been undertaken; an abundance of obvious ones remains. Every gain in definite knowledge has been accompanied by practical new questions yet to be answered by further research.

The most natural and most economic primary use of the new tools has been to apply them to existing crops. These efforts seem to have been almost fabulously productive when one contemplates the list of more than 200 consumer items that derive from the corn plant alone, and an equally long list from the relatively new soybean crop. That possibilities for further chemurgic exploitation of present crops are great cannot be doubted. Thus far some have been studied but little. Fundamental scientific facts, such as the precise molecular structure of starch, remain to be determined. Once found, a fact such as this might multiply the usefulness of starchy crops as raw materials.

The number of plants presently cultivated in the United States continues to be surprisingly small in comparison with the abundant diversity of the plant kingdom. Fewer than a dozen species will account for most of this country's agricultural production. Apparently not more than 200 species, if that many, are cultivated to the extent of producing carlot quantities, and probably 150 comes closer to the fact.

In contrast, some 15,000 species of plants are native to the United States and Canada. Estimates vary somewhat according to how far down the list of plant orders one goes, but the world total of plant species may be stated to be more than 250,000 and perhaps as many as 300,000. These are the species that botanists have discovered, classified, and described. Regarding most of them, present knowledge goes little further than description.

Every plant has something in it. Chemical content ranges widely. Since man has ready uses for cellulose, sugar, starch, proteins, oils, and other compounds, he has begun to look for those ingredients. Many other compounds also enter into plant composition, and as scientific knowledge expands there is always the possibility that some once valueless plant may provide a new compound of value and importance. A recent conspicuous example is Strophanthus sarmentosus, which has been found to contain a source material for cortisone, the new drug for arthritis. So little was known about Strophanthus, other than that it was a vinelike species of African origin, that no one could say whether it might be cultivated successfully in the United States what its habits were, or how it should be cultivated if supplies were required.

Knowledge regarding most of the quarter of a million species of wild plants on the earth stands at about the same stage.

Chemical records list many thousands of compounds that have been created during the course of experimentation. Whatever is known about any one of these appears in the chemical literature. No practical uses or applications have been found for most of them. However, a chemist, confronted by a new problem, can select from the records a list of these substances which, for one reason or another, seem worth investigation. One after another he tests them against his problem. If he is fortunate, he may find one among hundreds that meets his needs. In some such manner new insecticides, fungicides, and the weed killers have been made available to agriculture.

Little such comparable information yet exists about the diverse members of the vegetable kingdom. The names and shapes and habitats of thousands of plants are set down in the botanical records. Only in chance instances can the chemurgic investigator point to a species and expect that its specifications may meet some urgent need, because the specifications have not yet been determined or recorded.

THIS OPPORTUNITY alone opens up an almost unlimited area for future chemurgic advances. The future will no doubt see the entire flora of the earth, species by species, examined by the instruments and tests of the latest scientific technology. Chemical analyses will be made of leaves, roots, stalks, and fruits. Other scientific determinations will be made and recorded. Future investigators, seeking raw materials for processes to supply new and old human needs, will turn to such records, and will be able to select such plant species as may promise to meet their requirements.

The economic value of such information cannot be estimated. If it were available at this particular period in agricultural history, one would not be rash to expect that new crops would be in the process of becoming incorporated into American farm practices. If one of them were adapted to the Great Plains, and should promise enough profit to be preferred to wheat on a fourth or fifth of the present wheat acreage, the fear of wheat surpluses might quickly disappear. The same result might be expected if a new crop were found to occupy the cotton lands, potato lands, or any other lands where farmers yet have few alternatives to their present habits and methods of operation.