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NATURE 



\_Fcb. 6, 1 8 79 



If the plan were successful, other meteorological facts might 

 be determined by passing a current through mechanical indi- 

 cators attached to each piece of apparatus. 



Changes of temperature, electric conditions, and rainfall, 

 might ultimately be brought within the scope of such a plan of 

 telegraphic registration, and three or four floating observatories 

 might be arranged at considerable distances apart. 



The problem thus presented to the mechanician is the con- 

 struction of apparatus such that in passing an electric current 

 successively through indicators specially devised for each instru- 

 ment, readings could be made and announced to all concerned. 



By such means all coasts liable to be visited by progressive 

 storms might have timely warning of danger. 



The cost of such work would be very small in comparison 

 with the saving of life and property concerned. 



The Board of Trade might be induced to offer a substantial 

 reward for the most efficient mod4s of such floating stations. 



The essential feature of this proposal is, that new instruments 

 shDuld be devised as entirely different in form from those in use 

 as the aneroid is from the old barometer. 



There is no reason to doubt that whenever instruments are 

 devised in which the passage of an electric current can be made 

 through the indicators, it will be as easy to take readings of 

 meteorological instruments at the distance of a thousand miles 

 as when in sight, and with sufficient accuracy for the purposes 

 in view. A Hutton Burgess 



The Dissociation of Sal-Ammoniac — An Experiment 



All chemists admit that when sal-ammoniac is volatilised the 

 vapour consists, if not wholly, at least in great part, of hydro- 

 chloric acid and ammonia gases in the free state. But this fact, 

 so far as I am aware, is very seldom, if ever, demonstrated ex- 

 perimentally by teachers. The following modification of Pebal's 

 original experiment renders this proof very easy and available 

 for lecture purposes : — 



The stem of a long clay tobacco-pipe is passed loosely through 

 a couple of perforated corks fitted into the two extremities of a 

 piece of ordinary combustion tubing about a foot long. The 

 tube contains in the middle a small lump of sal-ammoniac, and 



near each end a strip of blue litmus paper. When the middle 

 of the tube is heated the vapour of the sal-ammoniac surrounds 

 a portion of the pipe-stem. If, now, a rapid stream of air or 

 any other indifferent gas is sent through the pipe, it is found to 

 be strongly charged with ammonia, so that it answers freely to 

 all the usual tests. At the same time the litmus papers contained 

 in the glass tube become red owing to the accumulation of hy- 

 drochloric acid in the residue. This experiment, of course, 

 depends upon the diffusion of the lighter ammonia through the 

 clay more rapidly than the hydrochloric acid also present. 



William A. Tilden 



The Sting of the Bee 



In "The Origin of Species," p. 242, fourth edition, Mr. 

 Darwin says, "If we look at the sting of the bee as having 

 originally existed in a remote progenitor as a boring and serrated 

 instrument, like that in so many members of the same great 

 order, and which has been modified, but not perfected, for its 

 present purpose, with the poison, originally adapted for some 

 purpose such as to produce galls, subsequently intensified, we 

 can, perhaps, imderstand how it is that the use of the sting 

 should so often cause the insect's own death ; for if, on the 

 whole, the power of stinging be useful to the social community, 

 it will fulfil all the requirements of natural selection, though ij. 

 may cause the death of some few members." In a lecture given 

 as it happens, this day ten years ago, I ventured to suggest tha! 



bees may have derived advantage, not in spite of the fatal con- 

 dition annexed to the use of their sting, but from that condition 

 itself, since "it may have proved expedient for a creature to be 

 armed with a weapon capable of inspiring terror, yet so con- 

 trived, that its possessor should of necessity be peaceful towards 

 its neighbours." It is very certain that many gentle-hearted 

 human beings wage remorseless war upon wasps, who would 

 never think of harming a bee or a bluebottle. On the other 

 hand there are many mischievous persons ready enough to trifle 

 with the feelings of a bluebottle, who keep at a respectful 

 distance from a bee, simply because they know it possesses a 

 certain power of revenge. In this way the sting is not, as your 

 correspondent " R. A." is inclined to think, worse than useless to 

 the individual bee, but an effective protection, albeit rather as a 

 shield than a sword. What is needed for its efficacy is not so 

 much intelligence in the bee as in those who would otherwise 

 attack the bee, and though to the individual bee a single expe- 

 rience ending in its own death could be of no avail, yet the other 

 animal, the wounded survivor in the fray, would have its under- 

 standing wonderfully quickened to the advantage of all bees it 

 might meet in the future. 



If, then, the bee is actually better off with its imperfect sting 

 than it would be with one theoretically more perfect, it may be 

 scarcely worth while to inquire whether a more effective weapon 

 could or could not be developed on the principles of natural 

 : selection. But assuming that under given circumstances bees 

 would derive advantage if the sterile workers had stings which 

 they could use without sacrificing their own lives, the very state- 

 ment of the hypothesis implies that a swarm, in which such 

 workers were developed, w'ould have an improved chance of 

 surviving in the stniggle for existence. Enemies would be more 

 certainly vanquished ; food would be more securely stored or in 

 greater abundance ; and thus the particular strain which had 

 produced the improved variety would be more likely than others 

 less favoured to be transmitted to future generations. The power H 

 of producing the better-armed warriors would be transmitted just H 

 as the power of producing the worse-armed warriors is trans- ^* 

 mitted, neither in the one case nor the other through the warriors 

 themselves. Thomas R. R. Stebbing 



Tunbridge Wells, February i 



Fossil Forests and Silicified Trunks 



In Nature, vol. xix. p. 257, the discovery of fossil forests 

 in the spring region of the Yellowstone River is referred to. I 

 have visited the United States National Park, and its geysers, and 

 observed exactly how silicified trunks in situ originate. All 

 geologists suppose that this must have happened beneath water, 

 and consequently Mr. Holmes supposes a constant alternation 

 of land and sea throughout a long period of subsidence. My 

 observations show the contrary, as silicified tranks originate only 

 in air, never in water. The siliceous hot water of the geyser basins 

 runs off periodically in another direction ; if it comes to a forest, 

 then all green leaves, all bark, and most of the branches fall off, 

 but the trunks remain erect. Now the siliceous water rises by 

 capillary attraction in the stem, but only on the outside of the 1 

 trunk does the siliceous acid become solid by drying in the air ; 1 

 from the outside the silicification of the wood cells enters very 1 

 slowly to the inner part ; the trunks are mostly struck dowTi by ' 

 the wind before the inner part gets petrified, and then the inner 

 part shows no ligneous structure, is only filled with foreign 

 matter, or sometimes with other minerals, or it is hollow, for the 

 inner wood decays. The white silicified wood is for a long 

 time soft, less coherent than common wood, and if such trunks 

 fall down into water, as I obsers-ed, they never get hard. Those 

 white forests without leaves, bark, and branches, are not rare 

 around the geysers. With my observations accord all characteristics 

 of silicified trunks, i.e. such carbonaceous trunks excepted, that 

 consist only of oulfiUed matter, stone kernels, for all real 

 silicified trunks are barkless, leafless, branchless, often with 

 inside hollow or partly filled, and always found along with 

 common opal derived also from geysers. 



Is silicification of trunks with well-preserved structure possible 

 beneath water ? No proof has yet been given. And further, 

 would it be possible for stems, which are lighter than water, to 

 remain in situ and erect by sinking under water ? Scarcely — 

 only if previously silicified and heavy. 



Besides, most statements of travellers on fossil forests relate to 

 the tropics. I saw several on my voyage round the world, which 

 consisted only of stems lying together. 



Leipzig-Eutritzsch, January 28 OXTO KuNTZE 



