52 



SCIENCE 



[Vol. XIX. No. 468 



One peculiarity of the drinking of the black drink is that, 

 so far as I can ascertain, it was not used at their meals as 

 we use tea and coffee, but wholly as a social beverage or at 

 festivals and other public occasions. I do not think the 

 women were allowed to drink it, at least not publicly. Au- 

 thorities differ on this point. 



Among the Creeks the women sometimes prepared the 

 black drink, but Narvaez writes that the Indians on the coast 

 of what is now Texas did not allow a ■woman to come near 

 it during its preparation. 



That a beverage containing caffeine should fall into disuse 

 and become almost forgotten is a singular fact. The use of 

 mate has not decreased from the time of the conquest of 

 South America by Europeans. The reason why the latter is 

 still in use and the former not lies, perhaps, in the fact that 

 the Europeans in South America mixed with the natives, 

 married, and adopted their customs, while the English and 

 French who settled the Gulf States did not associate with the 

 Indians, and adhered to the use of Chinese tea. Now that 

 we know that the leaf of the cassine contains caffeine or the- 

 ine, can its use as a beverage be revived? 



It is not as pleasant in odor and taste as Thea sinensis, 

 and this may be against it; on the other hand, it seems to 

 have some salutary properties which the latter does not pos- 

 sess, and may, perhaps, be far more cheaply obtained. 



A rough estimate can be made as to the number of square 

 miles upon which it grows. Estimating the coast line from 

 the James River, in Virginia, to the Rio Grande, in Texas 

 — about 2,000 miles — and multiplying this by 20 miles, the 

 extent of its growth inland, we get a total of about 40,000 

 square miles. On this area could be picked an immense 

 quantity of leaves, and if the trees are not destroyed in the 

 picking the crops could be harvested every year. No esti- 

 mate can be approximated even of the amount of the crop of 

 leaves which could be gathered, because we can not estimate 

 the number of trees on this area. 



It would seem possible that further inquiries on this point 

 and careful experiments in cultivation and manipulation 

 might result in furnishing our market with a product which 

 would be found in many cases an acceptable and useful sub- 

 stitute for the more expensive imported teas. 



mountain, rising far abore the adjacent country like Pike's Peak, 

 would produce rain if anywhere, I especially noted the weather. 

 Tremendous explosions occurred daily for some months. The re- 

 ports were often heard 30 to 40 miles, and many of them were at 

 elevations between 13,000 and 14,147 feet. Yet all this happened 

 in one of the dryest years ever known in Colorado, when often for 

 days or weeks there was no precipitation even on the mountains. 



G. H. Stone. 



Colorado Springs, Jan. 13. 



LETTERS TO THE EDITOR. 



**« Correspondents are requested to be as brief as possible. The writer^ s nam 

 is in all cases required as proof of good faith. 



On request in advance, one hundred copies of the number containing his 

 communication will fie furnished free to am/ correspondent. 



The editor willbe glad to publish any queries consonant with the character 

 of the journal. 



Rain-Making by Concussion in the Rocky Mountains. 



In connection with the recent discussions of the effects of explo- 

 sions in producing rain, it ought to be noted that for twenty years 

 or more the Rocky Mountains have afforded excellent opportunities 

 for observing the effects upon rainfall of heavy explosions at high 

 elevations. There are in this region thousands of mines, mining 

 claims with open cuts and adits, and quarries at elevations from 

 5,000 to 13,000 feet. Nitro-glycerine preparations are now the 

 explosives used in blasting. During the summer there is a great 

 amount of blasting high on the mountains. Several railways and 

 wagon roads reach 9,000 to 13,000 feet, and the grading of these 

 afforded much blasting. I have made considerable inquiry and 

 found no one who had observed any connection between the ex- 

 plosions and rain-fall. Probably few or none were especially on 

 the watch for such connection, but if there were any very obvious 

 connection it would have been observed, since there have been so 

 many years of opportunity. 



About two years ago the cog-wheel road was graded to the top 

 of Pike's Peak. Thinking that explosions on a high isolated 



Rain-Making. 



In Science for Nov. 37, 1891, appeared an article from the pen 

 of Professor Lucien I. Blake of the State University of Kansas, 

 entitled " Can We Make it Rain?" in which some suggestions are 

 made as to the proper method of conducting experiments to that 

 end, drawn from the discoveries of Mr. John Aitken of Scotland, 

 who has shown that unless there be dust particles in the air the 

 aqueous vapor therein contained will not, in condensing, form 

 itself into drops. Professor Blake argues from this that, instead 

 of using guns or apparatus for producing terrific noises, the better 

 way would be to send up inexpensive fire balloons carrying im- 

 palpable powders, which could be thus scattered through the air ; 

 or else carrying sulphur or gun-powder, the smoke of which, when 

 they were ignited, would furnish the dust particles, which, it is 

 assumed, are the only requisites for artificially setting in motion 

 the process of nature that brings rain. 



The reasoning of Professor Blake in leading up to this conclu- 

 sion and in combatting the idea that concussion is a necessary fac- 

 tor in artificial rain production, contains much that appears sound 

 from the standpoint of both science and good sense, and yet much 

 that will not bear examination. His contention that thunder does 

 not, to any extent, cause condensation of vopor, but is rather the 

 result of it, is one which I have always held to, for latent heat is 

 given out by condensing vapor, and this heat may appear in the 

 form of electricity, and cause the lightning-flash that makes the 

 thunder. The idea, also, that powder smoke may be a factor in 

 rain production when rain is caused by a battl°, is a logical de- 

 duction from Mr. Aitken's discovery. Professor Blake also avoids 

 the blunder committed by Professor Simon Newcomb, in his arti- 

 cle in the October number of the North American Revieic, where 

 the latter lays himself open to the imputation of being himself 

 guilty of the very thing he charges against the advocates of 

 the concussion theory, viz., of "ignoring or endeavoring tore- 

 peal the laws of nature." This he does by asserting that ten 

 seconds after the sound of General Dyrenforth's last bomb had 

 died away "everything in the air — humidity, temperature, 

 pressure, and motion — was exactly the same as if no bomb was 

 fired," thus abolishing at one stroke the principle of the conserva- 

 tion of forces. Professor Blake, with less zeal but greater wisdom, 

 practically admits that the forces brought into action by explosions 

 are resoked into heat, and he does not, like Newcomb, annihilate 

 this heat, though unwilling to admit that it can do work. Pro- 

 fessor Blake also has the good sense to recognize the fact that the 

 question of artificial rain production cannot be settled by labora- 

 tory experiments — a thing that cannot be said of all the assailants 

 of the concussion theory. 



But his contention that if concussion causes rain " the greatest 

 effect — the practical effect — must follow close upon the con- 

 cussion," cannot be sustained. While I reserve for a more ex- 

 tended article to be published elsewhere a full consideration of 

 this question, I will here say, briefly, that the well demonstrated 

 theory of the late Professor M. F. Maury that there are two great 

 atmospheric currents, the equatorial and the polar, flowing above 

 us in nearly opposite directions, furnishes the basis for a perfect 

 explanation of the reason why the centre of the atmospheric dis- 

 turbance caused by a battle should remain in the vicinity of the 

 battle-field while the two currents are mixing together and in- 

 itiatina; the process that leads to rain — a process which, it is 

 plain, must require time in reaching a state of effective action. 



But these points in the discussion are not so much what I desire 

 to consider at this time as the special method recommended by 

 Professor Blake for conducting rain-making experiments. The 



