By albert Schneider, M.D., Ph.D.
It is known that metals placed in water in which seedlings are stimulate growth, so long as the solutions of the metals are weak. Further, it has been determined that very minute quantities of the salts of einc and iron, as well as of silicates, have a stimulating effect upon the growth of some fungi. These and other similar observations led Hueppe to formulate his biological law or dictum which may be translated as follows: “Every substance which kills and destroys cytoplasm at a definite concentration will in hi bit growth and development in smaller quantities, and in still smaller quantities or weaker. Dilutions will, just beyond the point or threshold of indifference or neutrality, because a stimulation of the life processes.”
Acceleration of growth of higher plants, due to chemical stimulation, has been observed, but the writer is not aware that any extensive research has been done along this line, or that any considerable observations have been recorded. Copeland cites the well-known example of the more luxuriant growth of violets in the neighborhood of zinc factories It is also well-known that spraying with copper-sulfhate solutions causes increased growth, better development, and earlier ripening of fruit. Certain vapors, as those of ether, chloroform, alcohol, hydrogen, cyanide, carbon disulphide, and others, in high dilution, have a stimulating effect upon plant growth. In fact, Gardner and floriculturists make practical use of stimulating vapors, as of ether and alcohol, to induce a greater brilliancy, and a better unfolding of certain flowers.
Spores of fungi are variably affected by poison us substances. There is also a wide range between the strength of solutions which will inhibit growth and those which will kill. Mere uric chloride is the most toxic in its action on spores of fungi, while potassium cyanide, which is so extremely toxic to animals, is remarkably weak. Weak solutions of alcohol and sodium chloride have a stimulating effect upon the germination of spores. Uromyces spores respond very variably to copper sulphate; for example, a solution showed injury in several instances, while others grew in a solution as strong as. Potassium permaganate is of low toxic power.
With these introductory remarks I shall outline very briefly some tests with copper sulphate in Golden Gate Park, San Francisco.
For some time past a disagreeable odor had been noticed emanating from Stowe Lake, encircling Strawberry Hill, in Golden Gate Park. A microscopical examination of the water soil sediment and stems of some of the phenogams growing in the lake showed the presence of the following organisms:
- Oscillarias, in abundance.
- Diatoms, numerous species in great abundance.
- Desmids not abundant.
- Anabaena, quite abundant.
- Pediastrium sp., in great abundance.
- Filamentous fungi of the crenothrix and leptothrix types, quite abundant.
- Microbes, in great abundance.
- Protozoa (Paramecia), in great abundance.
- Rotifera, quite abundant.
- Vermes, of the vinegar-eel type, numerous.
- Crustanceanas, minute forms, abundant.
Other forms of plant and animal life were also present, but the organisms listed represented the dominant life of the lake. There were present millions of frogs eggs. The lake is extensively visited by coots and various species of ducks, which have come to look upon the body of water as their rightful heritance, and to feed upon the bread, cake, and crackers brought them by park visitors. There are also present tame ducks and swans. The catch net and dredge were not used in collecting material for examination, as it was thought that the material above referred to would suffice for the purpose. Two days after the microscopical examination was made fifty pounds of copper sulphate were placed in a gunny sack, fastened to a boat, and dragged through the water by rowing. The copper sulphate dissolved somewhat more rapidly than was anticipated, so that the water area was not uniformly covered, but as the lake is quite narrow throughout the greater part of its entire length this was not considered of any special consequence. The portions of the lake containing the most vegetable life was well gone over. The estimated strength of the solution was about one part to four millions by weight.
Eight days after the copper sulphate treatment another sample of water and sediment was secured from the same locality where the former sample was obtained, and examined microscopically. The result was most astonishing for one who did not have over much confidence in the entire proposed copper sulphate treatment of water supplies. Of the organism listed, all were dead with the exception of oscillaria, anabaena, and perhaps, microbes. With regard to the latter no opinion can be expressed, as no culture tests’ were attempted. Not a single wriggling worm, as no culture tests’ were attempted. Not a single wriggling worm, paramecium, or rotifer could be found. Quite a number of dead crustaceans (low forms) were found. No motile diatoms could be found, and the cytoplasmic contents of most of them had assumed a rich reddish-brown coloration. The oscillarias and anabaenas were apparently unaffected. Not a single living pediastrium was found, but it should be stated that many of these were found dead before the copper sulphate was applied. The bad odor from the lake was no longer noticeable. The few fish in the lake were apparently not inconvenienced in the least, and, of course, the ducks, coots, geese, and swans never detected the difference. Nor were the few water plants, as nuphar, sedge, and a few others, apparently injured in any way.
From the above test it would appear that diatoms and protozoa are peculiarly susceptible to the copper sulphate treatment. In the case of diatoms it is highly probable that the scilicious valves increase absorption. In the case of paramecia and other ciliated low organisms it may be that the ciliary motion and the rapid rate of ingestion of water solutions may account for the readiness with which they succumb to copper solution.
Without further discussion our present knowledge of the action of poisonous substances of high attenuation upon living organisms may be summarized as follows:
Hueppe’s biological law hold good in a general way, and is further supported by observations of the action of medicinal substances upon the human organism. For example, small doses of such nerve paralyzants as ether, chloroform, alcohol, strychnine, brucine, cyanides, etc. Act as stimulants; in large doses (comparatively speaking ) they paralyze and destroy life.