July 29, 1892.] 



SCIENCE. 



63 



science is; just what we may expect from it; just what we 

 have a right to demand from it. 



Take the single topic of the culture of plants. In how far 

 has that beea exhausted ? How much do we really know 

 about the reasonableness of our modes of cultivation ? How 

 much do we know about the effect of other modes of culti- 

 vation than those which have been in vogue for fifty, or one 

 hundred, or hundreds of years ? One suggestion in this direc- 

 tion may suffice as an illustration. If any man should sow 

 Indian corn in the same way that he sows wheat, with the 

 expectation of obtaining any crop of grain from it, we should 

 almost consider him an idiot. And yet I wonder whether 

 it is very much less idiotic to sow wheat in the way that we 

 do, with tlie expectation of attaining the best results possible 

 from this as a grain crop. I do not say that we do not get 

 a crop, often a good crop. A magnificent one, as compared 

 with what we have ever had, has been raised in the past year ; 

 but who knows whether the cultivation of wheat in some- 

 thing the same way in which Indian corn is cultivated, that 

 is, by giving it a much greater range for obtaining its nour- 

 ishment, and better advantages of light and air, would not 

 increase the yield by a very large percentage ? Indeed, 

 there have been some experiments, on not a very small scale, 

 which would seem to indicate that there are possibilities 

 in this direction which we have not yet even attempted to 

 ascertain. 



You hear a great deal from our own university experi- 

 ment station about the food of animals; and Professor Henry 

 is constantly experimenting to ascertain just what are the 

 best foods to produce a given result with a given animal. 

 He has endeavored to ascertain something of the effect of 

 different rations upon the bones, upon the muscles, upon the 

 fat of various animals. Why should we not have some ex- 

 periments carried on in regard to the food of plants ? Does 

 anybody know what the effect of a given ration of food for 

 a plant will be ? So far as I can recollect, experiments on 

 what we may designate as feeding plants, have been carried 

 on to a very limited extent. We have endeavored to ascer- 

 tain particularly where plants obtain their nitrogen; and for 

 the last twenty-five years, almost, this question has been one 

 under experiment and under discussion. I suppose that 

 many of you know something of the prolonged experiment 

 which has been carried on at Rothamstead ; and perhaps 

 some of you know of the recent experiments of Hellriegel 

 and Wilfarth, and Frank, men who are endeavoring to find 

 out whether plants, when kept in very vigorous condition, 

 can obtain nitrogen from the air, or whether it is absolutely 

 necessary to get it from compounds in the soil. Here is a 

 problem which has been attacked in the way these other 

 questions ought to be attacked, and in the very way in which 

 we may expect a solution of these thousands of other problems 

 in regard to feeding plants. The most recent experiments 

 in regard to this source of nitrogen for plants make it quite 

 possible that when plants are in a very vigorous and thrifty 

 condition they are then able to fix the free nitrogen of the 

 air; and that when they are not at their highest notch of 

 vigor, they are then able to get their supply of nitrogen 

 only from nitrogenous compounds in the soil. On this very 

 point we have some recent experiments that perhaps would 

 interest you ; and, bear in mind, I am only mentioning these 

 as illustrative. I am trying to show the necessity for such a 

 preparation in botanical study as will enable the men who 

 are most deeply and profoundly interested in this very study 

 to carry on some of those experiments that it seems so highly 

 desirable to carry on. 



Only a few months ago a paper was published by two of 

 the men who have been experimenting longest on this matter 

 of nitrogen assimilation ; and they give some hints in regard 

 to the harvesting of those plants which produce large quan- 

 tities of nitrogenous material that may turn out to be of very 

 great money value. It has been found that the contents of 

 leaves of clover, so far as nitrogen was concerned, was very 

 much greater at the close of the day, or near the close of the 

 day, than it was in the morning or during the forenoon. 

 That is, during the day, especially on bright and sunny days, 

 the plants were able to manufacture large quantities of these 

 materials. Now one of the main things for which our clover 

 crop is grown is the large amount of nitrogenous materials 

 which it contains as compared with other fodders. It is 

 quite plain that if these results are correct, the harvesting of 

 such a crop as this near the close of the day is going to give 

 us a fodder whose money value is decidedly greater than that 

 of one harvested early in the day, before the plant has been 

 able to manufacture these substances; for in the course of the 

 night the large majority of them are utilized for the plant's 

 own growth, and are converted into other forms of material 

 which are less valuable as animal food. 



But I cannot dwell upon that topic. Let me give you a 

 hint from another field. Perhaps if I should ask any of you 

 what is the purpose of the shade-trees along the streets of 

 our cities and villages the answer would be quite unanimous 

 that these trees were for shade and beauty ; and yet these 

 trees are not used for that purpose. At least nobody, I think, 

 would imagine that that was their use, if he passed along 

 the streets of our own city. He would think that the main 

 purpose of the best elms was to furnish adequate stays for 

 some electric pole or to support the telephone wires which 

 pass through them. He would suppose, if he saw the city force 

 making a street, that the chief purpose of the roots of the 

 trees was to be grubbed out of the way for the first curbstone 

 or sidewalk that the city wished to put along that way. If 

 one saw people trimming their shade-trees, he would think 

 that the main advantage of these was to afford an object les- 

 son as to how badly work could be done, and how much 

 injury could be inflicted upon an unoffending plant, appar- 

 ently with the intention of affording it early relief from its 

 sufferings by death. Our treatment of shade-trees in the 

 streets of cities and villages is one of the crying shames of 

 this day. Watch the " trimming " of street trees. Ignorant 

 laborers half chop and half break off the limb of a tree, and 

 leave the rough end exposed to wind and weather instead of 

 caring for the wound properly. We seem to think we have 

 no more duties towards that particular tree except toged rid 

 of a branch that may be a little bit in our way. We do the 

 very thing which will subject that tree to the greatest danger. 

 We oS'er the very best chance for the attack of parasitic ani- 

 mals and plants on that tree; as though our main purpose 

 was to destroy it, instead of our alleged intent, to trim it in 

 order to maintain and augment its beauty. 



This naturally suggests the management of forests. Man- 

 agement of forests ? We hardly know of such a thing in 

 this country. We do not manage our forests. We simply 

 cut them down, and then are glad that the cutters can move 

 on to some other acre and cut it down in the same way. We 

 have made almost no provision in this country for maintain- 

 ing our supply of timber. People may say what they please 

 about the inexhaustibility of our forest resources. Those of 

 you who have given the subject any attention Know that it 

 is utter folly to say that our forest resources are inexhausti- 

 ble, or that they are not being exhausted at a most extrava- 



