SERIOUS PROBLEMS OF SCIENCE TO-DAY
By Charles Baskerville, Ph.D.,
Professor of Chemistry, the College of the City of New York.
Dr. Charles Baskerville, whom we present this month to our readers, belongs to the younger generation of Southern men who are giving evidence of their capacity for leadership in fields other than political and forensic. Born in Mississippi in 1870, he is now, at the age of thirty-five, head of the Department of Chemistry in the College of the City of New York. After his graduation at the University of Virginia, he spent some time studying in Germany, and was called upon his return to the University of North Carolina, where he occupied the chair of chemistry. He is the author of a text-book on chemistry, and has written numerous articles on scientific, educational and technological subjects. He has distinguished himself in the field of original research and experiment, and belongs of right to the select band of scientific men who in these latter days, are so eagerly bringing to the light the laws that govern phenomena in the wonderful world of Nature.
The world to the human interpreter appears as a paradox of complexes. Scientific progress, during late years, has not been along the lines of the least resistance. One who has to do with the problems of nature is fascinated by the difficulties. Lord Rayleigh attached this motto to his recently issued, but already famous, “Collected Papers:”
“The works of the Lord are great
Sought out of all them that have pleasure therein.”
To be sure, the gratification of overcoming obstacles is often the only compensation.
Science has a wide range in the size and nature of the things with which it deals. With the microscope, it enlarges for vision the unseen world of bacterial life; with the telescope it draws the celestial bodies near and interrogates them with the spectroscope; it drags the lifeless element from the inanimate world, curiously plays with it and then puts it to man’s use, while seeking his origin and forcing him ever to show cause for his existence and right to question.
Much of the very recent work in physical science has distinct leanings towards metaphysics. It is scarcely to be wondered at, when the experimental data obtained appear to question tenets which devotees have become accustomed to regard as immutable. Facts are stubborn, however. When they cause the giving away of the least portion of the boundaries of our cherished systems, the imagination is unchained. The discovery and development of our knowledge of the wonderful phenomena of radio-activity, about which much that is true and more that is false have appeared in reputable journals of a not remote date, ensample the groping of our restlessness. These marvels, according to those who have worked with them most and whose opinions deserve the first consideration, spontaneously and continuously give out energy appreciable to the senses.
Where does this energy come from? Where does it go? One mudsill of science is the law of the conservation of energy. This division of science has a host of investigators busy with the problem of sustaining this fundamental. The harvest, which is not all grain but contains some tares, indicates that substances, which we have been pleased to regard as elemental constituents of nature, undergo voluntary alterations. Some appear to be breaking down into simpler matter, while others are building up. This virtually carries us back to the days of the alchemist.
It is a long story, which may not be related here, the deep-seated belief of most chemists in the unity, hence transmutation, of the elements. It is a far cry to its accomplishment, however. We need not go back to the time of the black-art for other examples of efforts to transform one element into another. Victor Meyer sought to build up thallium shortly after Crookes found it. Winkler dissipated Fittica’s transformation of phosphorus to arsenic. So chemists will be busy asking questions of Ramsay’s formation of a body like lead, through the agency of penetrating rays of radium.
Another foundation stone of science is the law of the conservation of matter. J. J. Thompson, from experimental work, explains certain observations by the existence of substances called electrons, a thousand times smaller than hydrogen, which we have regarded the lightest chemical element. The electrons appear to carry an electric charge. One farther step is then taken by the Cambridge professor, who says these corpuscles are electricity. They are attenuated matter. Electricity is a form of energy. We need no law for the conservation of the matter. Ostwald has taught that when one struck his shin on a chair in the dark, it was not the solid wood, but the force involved which produced the sensation. One would not have been conscious of the existence of the obstacle, but for the energy. Matter is energy.
Here one is on the boundary lines of experimental science and dealing with a metaphysical problem. It must not be forgotten, however, that two hundred years ago any suggestion of the Röntgen rays could well have been placed in a similar category.
Whether the explanations be accepted or not, it may be noted that Lodge has already illustrated, by beautiful lecture experiments, the possibility of a practical utilization of the facts of some of the observations. Fog is easily dissipated through the agency of electricity. The application of the principle on a gigantic scale, to a city like London, may yet be realized.
There are in the world, as is well known, numerous organisms belonging to the vegetable kingdom that do not resemble at all any of those things we are accustomed to look upon as plants. These bacteria are extremely small. They are from .00002 to .00004 inch in diameter. They are studied, not by ordinary vision, but by means of microscopes and by microscopes of only the very best kinds. They are, also, studied by their effects. They propagate very rapidly. Starting with one organism they may grow, within twenty-four hours, to 281,470,000,000 individuals. This rapidity of growth does not actually take place in nature; it is checked through natural conditions, or through excretions of the organism inhibiting such propagation.
We hear a great deal as to the production of virulent diseases through the agency of bacteria; but, while there are evil bacteria, there are, also, bacteria that are good. In short, we may understand, that all good bacteria are not dead bacteria. These bacteria exist in very large numbers in the soil. The upper portion of rich garden soil may contain, on an average, from one to five millions per cubic centimetre. This number may be very much greater, depending upon the amount of decomposed matter that is present and the favorable conditions for their propagation.
We are accustomed to think of bacteria as living only on the richest food and being the cause solely of putrefaction. This is not true. There are bacteria that live on the bare rocks and get their sustenance from those rocks and the surrounding air. Under these conditions they actually store up food material. They are really miracle workers. They render the soil fertile and the farmer is largely dependent upon them for the growth of his crops. They reduce mineral substance to the powdered form, assist in storing up organic matter for the soil and thus render it suitable for the growth of higher plants.
Under the influence of sunlight the green portions of plants, by absorbing carbon dioxide from the air and water from the soil, produce starch, which is one of the important foods for animals. This is not the work of bacteria, yet some of these organisms are capable of accomplishing similar work in the dark. It has been suggested that they derive their energy directly from the oxidizing processes that they set up. This is one of the problems of the soil bacteriologist.
Many micro-organisms act upon nitrogenous matters and destroy them, in that the substances are rendered less available for higher plants. These are denitrifying agents. There is another class of these micro-organisms, however, that takes nitrogenous food, which is only a little or not at all utilized by higher vegetables, and makes it available plant food. These micro-organisms thus contribute to the fertility of the soil. They oxidize ammonium compounds, from whatever sources they may be had, and form nitrites first and then nitrates. The nitrates are used by common plants. The nitrifying bacteria are composed of two groups of active agents: one group serves to make the first change, namely from ammonium compounds to nitrites; and the other, to change the nitrites to nitrates. The conditions most favorable for their activity are just the opposite for most other micro-organisms. In a soil having much organic matter already decomposed, these bacteria may be practically inactive until the decomposition has passed certain stages. During this transition, the soil is barely suited for crops. Nitrification requires the oxygen of the air; denitrification can go on in a compact soil with the least portion of the atmosphere. So really the soil is cultivated largely to favor the growth and propagation of the nitrifying bacteria. The result of experimentation has shown that this may be facilitated in some cases by denitrification first, and in other cases by stirring the soil for the penetration of the air, and again by applying lime to the soil to overcome the acidity. Professor Burrill recently said, “Some day farmers will come to understand that specialists working in the laboratory, and for years gazing through microscopes, are gaining knowledge for them.”
While many bacteria do not necessarily render food available for plants, they are most valuable in putting useless matters out of the way. One of the absolutely essential chemical elements for the growth of plants is nitrogen. It is most expensive. It is present in the greatest unavailable abundance, constituting three-fourths by weight of our entire atmosphere, and it is, also, the one element most likely to be deficient in the soil. It constitutes an essential constituent of albumenoid material. Under the influence of the denitrifying bacteria, it is converted into ammonium compounds, which are converted then through the nitrifying agents into nitrates. The nitrates are extremely soluble in water; consequently, there is no tendency towards the accumulation of the valuable food matter in the soil, as the same is leached out. The growing green plant is surrounded by the food that it wants but, as with the Ancient Mariner, there is not a drop to drink. Green vegetation cannot, or only to a limited extent can, absorb and utilize directly the free nitrogen of the air.
As a result of a long series of experiments, it has been learned that there grow excrescences, somewhat similar to galls, on the roots of certain plants. These natural structures have a character peculiar to the species of plants on which they occur. In a manner not understood, these tubercles, inhabited by bacteria, are capable of securing sufficient nitrogen from the air for their own growth, when the soil is practically able to furnish none. Other plants, next door, without these nodules, will die of starvation.
The number of bacteria in these nodules is very great but, although countless, they are insignificant compared with those in the soil outside. Those within the nodules, however, are specifically different from those without, perform different functions, and appear to be characteristic of the particular plant in which they exist. The leguminous plants, as peas, beans, clover, have these peculiar nodules. Other plants, however, like maize, cotton, wheat, are devoid of these assistants.
It has been known for a long time that the fertility of the soil could be augmented by rotating the crops and thus adding nitrogen to the soil by means of these leguminous plants. One of the problems engaging the attention of scientific agriculturists at present is to learn whether or not these leguminous organisms may be made to form tubercles on other plants, as for example corn or wheat. The importance of the successful issue of such experimentation requires no emphasis. While successful results have not yet been reported, something has been learned: namely, the fruit of corn may be very much modified in its chemical composition by breeding. Grain very much richer in nitrogenous matter has been grown by changes in the breeding. Such grain is a better food.
This is indeed a day of almost excessive specialization in science: Great things have been accomplished by the intense method. Some have thought, and spoken their thoughts, that such tended to carry men of science away from the contemplation of a unit or the system as a whole. Not a few have argued, perhaps with reason, that the great generalizations, as for example Darwin’s theory of evolution, were no longer to be hoped for. It is impossible for any single brain to follow the details of the varied branches of science. It is rare that one man pretends to know the detail of that division of science to which he gives attention. It is equally true, however, that many systematic minds are gathering, collating and publishing in readable form accurate summaries of details in the several branches. Men of broader vision are gathering these authentic digests and offering concepts, which encompass the phenomena of the Universe.
Such have been hinted at as the efforts of some to do away with what we have been pleased to term axiomatic truths. Whether this be desirable, is really of no moment. The facts point to the present movement of efforts to simplify matters. The most beautiful things after all are the simplest. This idea, of course, should not convey the impression of being boldly plain.