3° 



SCIENCE 



[Vol. XX. No. 49- 



One of the great difficulties in the way of an intimate 

 knowledge of the relations of plants to soils lies in our ig- 

 norance of the laws of assimilation in the plant. The con- 

 ditions under which the chemist studies these are of necessity 

 artificial. He cannot be assured that he has even measura- 

 bly reproduced the conditions of nature, and hence cannot 

 be sure that similar results will be attained under such most 

 natural conditions. Those most complex and peculiar 

 changes which occur in chemical compounds under what, 

 for want of a better term, are denominated "vital forces" 

 can never, at least under the present limitations of knowl- 

 edge, be fully uuderstood. And right here is the gist of the 

 whole matter. A knowledge of the chemical constitution 

 of a soil must precede a study of its relations to the full or 

 incomplete, as the case may be, development of a plant de- 

 pendent on it for nourishment. In other words, the consti- 

 tution of a soil is a determinable quantity, the life-processes 

 of the plant constitute an indeterminate quantity, and the 

 relation of the two is the thing sought. No amount of 

 chemical experimentation can bring into view the unknown 

 factor. 



The various experiment stations which are now estab- 

 lished in every State in the Union can do much toward 

 clearinff away a great cloud of agricultural superstition rel- 

 ative to these subjects. There should be place for the theo- 

 retical as well as the practical in their work. It should be 

 clearly shown that the constitution of a soil has far more to 

 do with the growth of a crop of corn than the moon, or than 

 any other of the oft-quoted and still entertained notions of 

 strange and hidden forces. Tall oaks do not grow from 

 little acorns except under the most favorable conditions of 

 soil, and these conditions, again, are affected by the innu- 

 merable changes which occur in temperature, moisture or 

 other variables, which render more or less tractable the va- 

 rious compounds on which the plant must feed. 



The chemist who studies a soil does so by the same meth- 

 ods as those by which he would examine an unknown min- 

 eral, and usually with no greater care. He wishes, simply, 

 to know what elements may occur in it, under what condi- 

 tions, in what abundance, to what degree they may be dis- 

 sociated, and whether there be present any substance which 

 would interfere with their assimilation by the plant. In 

 this way he arrives at a fair knowledge of the sample, but 

 he can tell you little of its value for agricultural purposes. 

 He here depends not on his. knowledge of soil constitution 

 or of its genesis, but on the facts of observation, which are 

 familiar to every farmer, and which he unconsciously con- 

 nects as cause and effect. It does not need a chemist to tell 

 an observant farmer that he will not be likely to reap a 

 strong growth of wheat from a sandbar. He has had as an 

 instructor an experience in the relations of crops to the labor 

 expended on them that led him to definite and valuable con- 

 clusions on this matter. But there are innumerable ques- 

 tions which he may put to the chemist and hope for aproBta- 

 ble answer. When once the soil has been exhausted of a 

 necessary constituent he may learn from experience that this 

 or that material judiciously applied will remedy the defect. 

 The farmer, moreover, has yet to learn that, even in Iowa, 

 there cannot be a constant draft on a soil and the same crop 

 be produced with equal value each year for an indetermi- 

 nate number of years. Each crop lessens the productive 

 power of a soil by the amount of material which it removes 

 from the soil each season. Here it is pussible for the chemist 

 to aid the producer by telling him exactly what has been 

 taken from the soil, and thus indirectly telling him what is 



needed in the compost he may apply. This borders on or- 

 ganic chemistry and does not at present concern us. 



Among the substances which must be present in a soil to 

 give it an average degree of fertility stands pre-eminent the 

 compound known as phosphoric acid. But this substance 

 does not exist in the soil except in combination with some 

 other substances, known technically as bases. These sub 

 stances are commonly, if not always, iron and alumina, with 

 which they are 'in such chemical combination as to form 

 salts known as phosphates. It is, however, not sufficient to 

 know that these compounds are present. We must further 

 know whether they are so associated with other compounds 

 as to be readily disintegrated and rendered soluble, for un- 

 less soluble they cannot be used as plant-food. Now, ueithei' 

 of these compounds of phosphoric acid — i.e.. iron and alu- 

 mina phosphates — is available in that form. Experiment 

 has shown that the form in which tbese substances are avail- 

 able is that of calcium (lime) phosphate. That this has a 

 relation to the amount of calcium silicate in the soil is 

 clearly proven, and that by a process of double decomposi- 

 tion of the three compounds the available one is obtained is 

 also well known. But this process has not yet been cer- 

 tainly traced in nature. As stated at the bsginning, it is 

 right here that the processes of the laboratory and those of 

 nature need to be connected. Whether they ever will be 

 depends upon the support given to the great army of practi- 

 cal chemists whose attention is now directed to the theoreti- 

 cal features of agricultural chemistry. 



It should be a matter of congratulation to the farmers of 

 Iowa that work along these lines is now progressing very 

 favorably at the experiment station at Ames. A vast 

 amount of valuable information may be expected from this 

 source, and in due course of time it will come. 



CURRENT NOTES ON ANTHROPOLOGY. — X. 



[Edited by D. O. Brinton, M.D., LL.D.'i 

 The Ancient Libyan Alphabet. 



In Science, May 8, I called attention to the new light 

 thrown upon the history of our alphabet in its ancient form 

 by the researches of Dr. Glaser among the ruined cities of 

 Arabia. Another curious study in the same line is that 

 offered by the Libyan alphabet. It appears to have been in 

 common use among the BerbBr tribes of North Africa long 

 before the foundation of Carthage, and is still employed 

 constantly by the wild Touaregs of the Sahara. It is not 

 the same as the Iberic alphabet of Spain, and in its forms is 

 almost entirely independent of the P^hoenician letters. It is 

 composed of consonants, called tiflnar, and vowel-points, 

 known as tiddebakin. The latter are simple dots, the for- 

 mer are the lines of a rectangle, more or less complete. 

 Several of them are found in the oldest Etruscan inscriptions, 

 and on that known as the ''inscription of Lemnos." Sepul- 

 chral epitaphs in this alphabet have been discovered dating 

 two or perhaps three centuries before the Christian era; 

 while rock-inscriptions of perhaps more ancient date, show- 

 ing extremely archaic forms of the letters, have been copied 

 from localities in the southern Atlas ranges. 



The writers who have given especial attention to this little- 

 known subject are Faidherbe, Duveyrier, Halevy, Bissuel, 

 and, recently. Dr. CoUignon, who has a brief summary of 

 results in a late issue of Les Sciences Biologiques. 



The Aborigines of Asia Minor. 

 The artistic and linguistic studies into the proto-ethnology 

 of Asia Minor (see Science, May 20) are happily supplemented 



