October i6, 1891.J 



SCIENCE. 



2 1<^ 



brutes: is there to be no improvement in that direction? It has 

 been proven that modifications are taking place in his dental 

 armature, his dermal appendages (as the hair disappearing, and so 

 forth), and perhaps to some extent in his very form, due to dress, 

 as encasing the feet, and strapping certain parts of the body. Will 

 these causes not, if continued, produce their ultimate effects? 



However daintily he may mask the animals he kills and devours, 

 he is still as carnivorous as most of the Felidce. He often settles 

 his disputes by the murder of masses of his kind, and the leaders 

 in such assaults are glorified by having monuments erected to 

 them in the high places. In these days such monuments are seven- 

 ty-five per cent more numerous than are those erected to the great 

 among men of letters, of science, the arts, and the industries. All 

 of this savors very strongly of savagery, and can hardly be char- 

 acteristic of a tully developed race of men. 



This aspect is not improved when we come t-o think of the va§t 

 number of what many in the world would reckon as our best de- 

 veloped specimens of men, whose minds are still controlled by the 

 nursery myths, the miracles, and the fables that were told and 

 sung to the children of the early peoples of the world in Asia. la 

 the mind of the man of the future to remain in such a condition 

 of thraldom? In fact, the most of the opinions held, the institu- 

 tions, the very language, the entire organization by and of the 

 best existing t\pes of men, are each and all to me highly indica- 

 tive of a very early stage of the development of the species. 



So I cannot fully coincide with Dr. Langdon when he says, 

 " While, therefore, we may anticipate an mcrease in the average 

 perfection of parls, and consequently a more harmonious develop- 

 ment of man's present plan of sti-ucturp, we cannot rationally look 

 for any radical change in the plan itself." Although it would not 

 demand any radical change in the plan of structure of present 

 man, has it ever occurred to your correspondent that in the dim 

 future of the world the environment of man may have progres- 

 sively so changed as ultimately to produce a race of enormous 

 giants; or, other conditions obtaining, a race of the veriest pyg- 

 mies may be the result ? Who among our present-day naturalists, 

 had he lived in Eocene time, and become familiar with the little 

 Kohippus, no bigger than a fox, would ever have predicted that 

 from it was in time to be developed the highly modified modern 

 horse? It is safe to say, not one, — yet Eohippus must have ap- 

 peared quite perfect for its kind in its day. 



There is every reason to believe that in the lapse of time, or 

 when many more millions of years have rolled by, our little earth 

 will become cold from changes now going on: she may solidify to 

 her very core, and become as frigid as a moon, and utterly incapa- 

 ble of supporting any manner of life upon her surface. In fact, 

 life will probably be at an end long before any such condition in 

 her comes about. The last one of the human species, the very 

 last individual of all, the very tip of the last twig of the tree of 

 human descendants, must also die, — perish. If that modified 

 form possesses sight, its eye may look out upon a remarkable 

 scene indeed. Earth may be stripped of all timber; coal beds all 

 burned up; metals all moulded into medallions, machines, and 

 monuments; her land-surface graded nearly or quite level by 

 causes now in operation; every other living thing, every lion, 

 lark, and louse in the land exterminated; and nothing remaining 

 but the works of the modified man. ''~^- R. W. Shufeldt, M.D. 



Takoma, D.C., Oct. 9. 



Rain-Making. 



In Science for Oct. 9 Mr. Powers takes exception to a short dis- 

 cussion of this question prepared by myself and published in 

 August. I have no desire to enter the discussion, but simply to 

 correct one or two misapprehensions of my own connection with 

 this matter. Mr. Powers gives a novel view of Plutarch's state- 

 ment regarding battles and rain. The following is a translation 

 of Plutarch : " Extraordinary rains generally fall after great bat- 

 tles." He is doubtful whether by these the gods would wash out 

 the trouble from the sky " or the blood and corruption, by the 

 moist and hea^y vapors they emit, thicken the air, which is liable 

 to be altered by the smallest cause." It hardly seems as though 

 this corresponds with the later view of .Mr. Powers. But the view 



of another rain-maker does not agree with that of Mr. Powers 

 "Let 10,000 Greeks march into battle chanting their 'paeans' 

 and shouting their 'allallas,' beating time meanwhile on their 

 shields, while 100,000 Persians are advancing against them, con- 

 tinually shouting their terrible battle-cries; then let the great 

 armies rush together with the tumult of clashing swords and 

 shields, the hoar.^e death-cries and shouts of victory, and surely 

 the sound-waves rising from such a din will literally shake the 

 heavens, and are capable of producing no insignificant effect 

 among the volatile currents of the upper air. Moreover, the heat 

 generated from the struggling: masses and the moisture evaporated 

 from their perspiration would exercise a decided influence in dis- 

 turbing the equilibrium of the atmospheric conditions." 



Exception is taken to my very guarded statement, " During the 

 war of the Rebellion there were over 3,300 battles, on an average 

 prohahly as severe as the average of the 158 above mentioned" (by 

 Mr. Powers). I have italicized a very important word. I had no 

 time to do anything more that compare several of the running 

 statements of the battles given in the old edition of " War and the 

 Weather ' with other facts. This I did sufficiently to satisfy my- 

 self that such a statement could be made. It is an open question 

 in my mind just how one should treat a continued battle and firing 

 in studying its probable effect upon the atmosphere. The more or 

 less desultory firing in many battles could not be considered as of 

 much importance. Moreover, any rain which fell after an interval 

 of a few minutes must probably be regarded as in no wise due to 

 the explosions. I do not say that the smoke and carbon from the 

 powder might not have some influence, but whatever they had 

 would be felt a hundred miles or more from the scene of the ex- 

 plosions. 



Mr. Powers thinks that the currents of the atmosphere do not 

 travel-atthe rate of twenty to fifty miles per hour, or, at least, dur- 

 ing these battles they did not do so. This is a question of fact which 

 has been proved by actual observation, and cannot be gainsaid. 

 The only time these currents are not moving with this velocity is 

 when a high area or " clearing condition " is passing. Mr. Pow- 

 ers's theory of storm formation is exceedingly unique, and possibly 

 he could help meteorology by establishing that theory. What he 

 would need to do would be to select a high area or a " clearing 

 condition." and then make his explosions and note the result. It 

 certainly is not a fact that two currents pass in opposite directions 

 near the point of formation of our storms. Mr. Powers takes ex- 

 ception to my statement, "One thing seems very evident, that 

 absolutely no rain can be obtained out of a dry atmosphere." I 

 will now take out the word "seems " which has no business in 

 this statement, and leave the rest without fear of contradiction by 

 any one who reads the expression as I meant it. 



H. A. Hazen. 

 Washington, D.C., Oct. 12. 



BOOK-REVIEWS. 



Laboratory Practice. By Josiah Parsons Cooke, LL.D. New 

 York, Appleton. 16°. $1. 



All students of chemistry are familiar with "The New Chem- 

 istry," by Professor Cooke, the first edition of which appeared 

 eighteen years ago, when it was one of the earlier volumes of the 

 International Scientific Series. That book, which has fascinated 

 so many, now appears in a revised and enlarged form. The book 

 now issued is described by the author as a " companion volume to 

 ' The New Chemistry.' " As will be remembered, the earlier book 

 waslargely descriptive of the problems and theoretical discussions 

 of modern chemistry. • ' Laboratory Practice " gives a series of ex- 

 periments on the fundamental principles of chemistry. The pur- 

 pose of the author is to furnish the beginner in chemistry with 

 a text-book which shall aid him in doing his laboratory work, but 

 only when this work is carried out under the guidance of a com- 

 petent teacher, — a teacher who can speak to the students from 

 the fulness of his own knowledge. Professor Cooke, as the head 

 of the chemical department of Harvard College almost as long as 

 there has been such a department — for more than forty years — 

 has had great experience as a teacher of chemistry, and it is cer- 

 tain that each and all of those who have had the pleasure of tak- 



