NATURE 



{Dec. 3, 1874 



British Association, at its meeting at Bradford, appointed a com- 

 mittee, tlie function of which was to see what arrangements of 

 this nature could be carried out. I am not aware, however, that 

 the committee has ever made any report, or if it h-)s arrived at 

 any conclusion on this subject. Inquirer 



Nov. 24 



Discovery of Remains^of Plants and Insects 

 1 TiiiN'K I informed you .ibout two years ago of the discovery 

 of a bed of plants, with leaves, and a great variety of seeds, m 

 this locality ; also the wings of a Libellula, and the beak of a 

 bird. As little interest was attracted, I have not hitherto 

 informed you of the subsequent finding of a bed of insects— Ihes, 

 gnats, and the larva and pupa of the latter, the larva in count- 

 less thousands— also the wings, in great numbers, of a variety of 

 flies, butterflies, and one or two grasshoppers ; also a wmg 

 resembling that of the Mole Cricket. There are, likewise, two or 

 three beetles. The insects and wings are frequently associated 

 with a very pretty Lymnea, in considerable numbers, and an 

 occasional Planorbis, both retaining a high polish. I have also 

 noticed a solitary small white Cyclostoma in the same bed. There 

 are, I think, two feathers among the specimens obtained. Per- 

 haps, as some interest has been shown in a similar discovery in 

 Scotland, some of your readers may like to be informed of this. 

 I am much indebted to the Rev. T. G. Bonney, of St. John's 

 College, Cambridge, to whom you referred me, for advice and 

 encouragement in examining these beds. 



Gurnet Bay, Nov. 23 E. J. A'CouRT Smith 



Sounding and Sensitive Flames 



In a letter which I have just received from Dr. A. K. Irvine, 

 of Glasgow, my attention is drawn to a short abstract of some of 

 his experiments with Barry's sensitive tlarae, which appeared in 

 the English Mxhanic oiVte.c. 15, 1S71, a few months previously 

 to the appearance in the Journal of the Franklin Institiilc, and 

 in the American Journal of Science, of the description, referred 

 to briefly in my last letter {Nature, vol. xi. pp. 6 to 8), of .Mr. 

 Geyer's researches on the acoustic properties of the same flame, 

 some particulars of which Dr. Irvine appears also to have noticed 

 independently. The few lines in which his observations are 

 recorded corroborate so fully the character and mode of action 

 of the fl.ame as now pretty perfectly established, that a short 

 extract from them will scarcely be without interest, from the 

 satisfactory support which it offers to the accounts and explana- 

 tions that other investigators of this flame have elsewhere given 

 \\ graphic terms of its appearance. 



After noticing that it can be produced with an oi-dinary street- 

 lamp burner (perhaps the straight quill-form, still to be met with 

 in some streets of Glasgow, is here meant), as well as with pin- 

 hole jets of steatite ; and that whatever kind of gauze may, with 

 slight differences of the effect, be used, the further the wire-gauze 

 can be removed from the burner without the flame breaking or 

 flattering (? fluttering) on the gauze, the more sensitive is the 

 flame, — Dr. Irvine continues to describe the further characters of 

 the flame as follows : — 



"4. The roaring which takes place when any sound disturbs 

 the flame is evidently in consequence of the greater proportion 

 of air which mixes with the gas before passing through the wire- 

 gauze ; in short, wlien it roars and flattens on the gauze, it is an 

 explosive mixture that burns. 



"5. If a suitable tube (for instance, a paraffin lamp chimney 

 of proper dimensions) is placed on the wire-gauze, it \\ ill be 

 found that a musical note is produced every time the flame is 

 disturbed by a sound with which it sympathises. 



** 6. A mixture of any inflammable gas and air passing through 

 wire-gauze, over which a suitable chimney is placed, will give a 

 note varying in pitch with the dimensions of the chimney and 

 size of the flame." 



Proceeding on this principle. Dr. Irvine adds that he had 

 recently constructed and patented a form of miner's safety-lamp, 

 which, when an exjilosive mixture of gas and air enters it, gives 

 an audible signal of the dangerous condition oi the mine. 



It may be questioned if it is quite safe to excite rapid vibra- 

 tions of a gas-flame burning on the wire-gauze inside a safety- 

 lamp placed in an explosive atmosphere ; but if any vibrations 

 of the flame that are thus produced are limited (as it appears 

 possible to ensure, by a proper construction of the lamp) to the 

 extremely small oscillations of a high-pitched note, then no 

 elements of danger in this new contrivance need necessarily be 



introduced or apprehended from the sounding action of the 

 flame. In this and in other cases of their employment which 

 have suggested themselves to experimenters on the acoustic pro- 

 perties of gas-flames, there seem to be hopeful promises of ad- 

 vantageous application of the sensitive and sounding properties 

 that certain gas-flames jiossess in a very high degree. But it is 

 to the explanation of the cause of the prostration,^ and to the 

 account of the case of musical sensitiveness in Barry's wire-gauze 

 flame when disturbed by external sounds, that it is particularly 

 desired to direct attention in t\ie foregoing extract from Dr. 

 Irvine's brief description. Tlie reason that the author assigns to 

 them, and thence to the monitory action of his singing safety- 

 lamp, that increased inflammability of the burning gas-mixture 

 is at once the source of the sensitiveness, silent or sounding, of 

 the wire-gauze flame, and the .necessary condition of the atmo- 

 sphere for the alarm note sounded by the newly invented safety- 

 lamp, is so clearly expressed and illustrated by the order of his 

 experiments, that as regards the probable mode of action of the 

 disturbed gas-current adopted to explain the sensitive effects 

 observed, there can be no doubt of the correctness of Dr. Irvine's 

 view. 



The gas-current, before reaching the wire-gauz,-, will naturally 

 entangle and mix with a larger quantity of air when it is dis- 

 turbed, by presenting a greater surface to the air in that state 

 than when it issues smoothly. In the latter case it is not 

 inflected into the tortuous wave-line of many folds and curves 

 into which it must be bent on leaving the burner and passing 

 from a fixed jet into an atmosphere oscillating rapidly to and fro 

 under the action of external sounds. The sound-«'ave of the 

 air into which it flows thus serves to incorporate more air with 

 the upward stream and to render the combustion of the mixture 

 more condensed and prompt, and the appearance of the flame in 

 consequence more contracted and boisterous than when the gas- 

 jet burns in a surrounding atmosphere of quiescent air. 



Newcastle-on-Tyne, Nov. 14 A. S. Herschel 



A"^ 



SCIENCE IN MUSIC 

 T the fjrst meeting of the Royal Society on Thursday 

 evening, the 19th ult., a paper w,\s read by Mr. A. 

 J. Ellis, F.R.S., on "Musical Duodenes." This formed 

 the conclusion of a series of papers (the preceding ones 

 having been published in the Minutes of Proceedings) on 

 Just Intonation and Temperament in Music. 



The author explained the defects of the ordinary keyed 

 instruments, such as the pianoforte and organ, which were 

 limited to twelve sounds in the octave, and were now 

 tuned by a system which he characteri-'ed as the " worst 

 possible," every element of harmony in them being put 

 out of tune in all keys. To produce just intonation, it 

 was necessary to have many more than twelve sounds in 

 the octave ; and he exhibited a chart giving a classi- 

 fied list of seventy-eight such notes, distinguished by 

 the ordinary musical signs, with the addition of certain 

 other marks which defined exactly the pitclr of the notes, 

 while their respective positions in the chart gave, by 

 simple inspection, a correct idea of their relations to each 

 other. Mr. Ellis then stated that as the large number 

 of notes required by correct theory became troublesome 

 in practice, the plan had been adopted of sacrificing 

 absolute truth in some instances, and introducing a trifling 

 error, by which means the requisite number of notes was 

 much reduced, while the error was so small as not to 

 offend the ear in any sensible degree. 



Having determined thus on the number of notes to be 

 used, the practical problem arose how best to introduce 

 them in an instrument. Many contrivances had been 

 suggested, involving new key-boards and modes of finger- 

 ing ; but considering the difficulty of introducing changes 

 of this kind, preference was given to other plans, which 

 retained the twelve notes of the ordinary key-board. To 

 enable such a system to be carried out, it was necessary 

 to make choice of certain sets of twelve notes, to be used 

 when playing in certain keys ; and to furnish information 

 to guide these selections was the chief object of the paper. 

 Such a set of twelve notes was called by Mr. Ellis a 

 musical duodcnc, and the chart exhibited many of these 



