Page 235

7i '  23,, 1 88 74]
NA TURE
is found necessary to produce and to maintain then.  Ill heat.
harmoniconls the action is less simple, the alternations of
pressure as well as the oscillations of the air determining the ad-
11iisslon of the entering puffs.  To judge from the position in
w'hih a singing-flame sounds best in a chemical harmonicon, a
certain " lead hlike that used in admitting steam  to the cylinder
of a steam-engine is necessary for the flames to exert their ex-
pansive force, the gas perhaps not instantly igniting on its
emergence from the jet ; and this " lead " lthe mere oscillations
of the surrounding air are unable to supply ; but in the
position which the jet occupies in the tube, the air-pressures,
which return at periods answering to a half stroke of the flame
before the oscillations, precipitate its development and enable it
to exert its pressures at the proper times.  The proportion of
lead given to the flame increases as it approaches the middle of
the tube, where only the variations of pressure act upon it, while
at the lower end of the tube it is commanded entirely' like the
air-blast of an organ-pipe, by the oscillations of the air.  It is
perhaps thus that a wire-gauze flame burning at the foot of a
lamp-glass sounds so vociferously, because stationaryalternations
of pressure in the lower part of the tube cannot affect the
transmission of gas through the gauze, while the extensive
oscillations there produced have perfectly free action in extin-
guishing and replenishing  the flame.   By using   a piece
of thin glass connecting-tube about 4 ft. long, held ver-
tically over an unlighted Bunsen jet, on lighting the gas
escaping at the top, and carefully raising the tube so as to allow
the flame to descend very slowly, it may be made to pause in its
descent at the successive ventral points corresponding to the har-
monic divisions of the tube, sounding the note of the section of
the tube above it as it comes to each point of rest.  On lowering
the tube it ascends, stopping and singing at some higher point of
rest, depending apparently upon the less instantaneous infamma-
bility of the gas.  With some difficulty, and by shielding the
lower end of the tube as much as possible from draughts, the
flame was sometimes made to drop quickly within a few inches
of the bottom of the tube, stopping always at the same place and
sounding there for a moment the lowest note of the tube, when
by the strength of its vibrations it was either rapidly extinguished,
or else lighted the Bunsen lamp below. The notes sounded by
these means were, however, not nearly so loud and effective as
those obtained when the gas-flame was held at its stationary
points by making it come to rest upon wire-gauze.
  I am indebted for almost all of the foregoing experiments to
Mr. Haigh, who was very skilful in suggesting and devising
modifications of them, leading to the immediate conclusions re-
garding the mode of their production to which they appear most
distinctly to conduct. Other occupations have hitherto prevented
me from attempting to extend and to examine them as thoroughly
as they seem to deserve; but the field of research presented by
the study of harmonic flames does not yet appear to he nearly
exhausted, and the repetition of the above experiments by
others will perhaps throw more light upon the doubtful questions
with which they are still to some extent surrounded, enabling,
it may be, the many significant and easily-recognised features
of singing flames to be produced with even more than their
present ease and certainty.              A. S. HERSCHIEL
               SCIENTIFIC SERIALS
  THE Ceoloe,ical Magazine, July.-In this number Mr. J. Croll
commences an article On the physical cause of the submergence
and emergence of land during the glacial epoch, which is to be
continued. As far as it goes it is concerned with the conceptions
we have of the thickness of continental ice. An attempt is made
to estimate the thickness of the great antarctic ice-cap, about
which "observation and experience to a great extent may be
said to be a perfect blank." The condition of the interior of the
antarctic continent is inferred from the little that we know of
Greenland. The diameter of the ice-cal) being taken at 2,800,
the thickness at the centre is given at the lowest at 6 miles,
reckoning a quarter of a degree only as the slope of the upp)cr
surface. Mr. Hopkins has recorded that he found one degree the
least slope on which ice will move. Ani ice-cap of only 6 miles
in thickness is to many an unfamiliar idea, and "few things,"
Mr. Croll writes, " have tended more to mislead geologists in
the interpretation of glacial phenomena than inadequate conclep
dlons regarding the magnitude at continental ice.' -The other
original articles are On the dawn and development of life on the
235
earth, by If. Woodward, F. R. S. --Notes on carboniferous mojno.
myaria, by R. Etheridge, jun.-T1he geology of the Nottingham
district, by Rev. A. Irving. Therc are two letters on the glacia-
tion of the south-west of England, by Dr. Mackintosh and II. B.
WVoodward.-Mr. Mallet writes that he does not see how he can
be charged with " inisapprehen(ling " Mr. Scrope in the discus.
sion on the nature of volcanic heat, and asks that as he has
reduced his own views to clear definition (Phil. Trans., vol. i.
187;,) Mr. Scrope will do the same.
   Bu/letin (le I'A1,Acadmie A(7e/.' (/tS Scidnces, &r., tie Re/hiq ue,
 No. 5.-M. Van 1'eneden contributes the first part (65 pp. in
 length) of a paper entitled " ( )n the original distinction between
 the testicle and the ovary; the sexual character of the two pri-
 morial layers of the embryo; the morphological hermaphrodism
 of an entire 'individual'; an essay on the theory of fecundation."
 The " essay " opens with an introduction in which reference is
 made to Huxley's first pointing out that the organism of Zoo-
 phytes, Medusidne, Polyps, Siphonophora and Hydroidexe con-
 sists essentially of two layers, endoderm and ectoderm, and also
 to other writers who have studied the relationships of endoderm
 and ectoderm in various aspects. The second part contains the
 history and bibliography of the subject, and the third (50 pp.
 long) describes the author's researches on Ifydractiniai ec/inala,
 made during a lengthened visit to Ostend. He first describes
 the characters which the male and female reproductive zooids
 have in common, and carefully details his methods of prepara-
 tion. The microscopic description of the female and then of the
 male zooids or gonosomes is given in much detail, illustrated by
 plates. He arrives at the following conclusions :-The ovaries
 are developed entirely from the epithelial layer of the endoderm.
 Up to the time of maturity they remain entirely surrounded by
 the elements of the endoderm. The testicle and spermatozoa
 are developed from the ectoderm. The female sporosacs contain
 rudimentary testicular organs, and male sporosacs a rudimentary
 ovary. From a sexual point of view the ectoderm and endoderm
 have an opposite signification. If it is true that special organs
 have resulted from specialisation of function following division
 of labour, then we must believe that originally the whole ecto-
 derm performed the male sexual function and the endoderm the
 female. The ectoderm is the animal and male layer, the endo-
 derm the vegetation and female. Fecundation consists in the
 union of an egg, the product of the endoderm, with the product
 of the ectoderm, which brings chemical compounds of " opposite
 polarity " into union. The new individual is formed at the in-
 stant the elements of " opposite polarity" unite just as a mole-
 cule of water is formed by the union of atoms of hydrogen and
 an atom of oxygen.-WI. Henry contributes papers on chloral
 and chlor-ethylic ethers, &c.-M. F. Plateau has sent in a com-
 munication on the digestion of insects, which is to be published
 in the memoirs.
 Bu/letin tie Az Socei.e d'Anth/ropoo-ie de Paris, t. vii.-In the
 seventh volume of this journal M. Hamy gives us the results of his
 examination of M. Janneau s officially conducted investigations
 into the anthropology of Cambodia. He begins by endeavour-
 ing to define the meaning attached to the three words, "  Moi,"
 "    Kha," and "Penang," which have hitherto been used
in
 Annamite, Laolian, and Kmer almost indiscriminately to indi-
 cate the wild tribes of the hills. By the first of these we must
 understand the negro tribes occupying the oriental chain of the
 Cambodian range; in the second a people not unlike the yellow
 races of Laos ; and in the third the tribes in whom the flat-faced
 non-Caucasian type is strongly marked.   The Cambodians
 themselves distinguish between races, known as K    u  i, who,
 they say, are the primitive people of the land but not savages,
 and the Rode, the former being employed in the extraction of
 the ores of Kompong Svai, and the latter in the breeding, and
 care of horses, while both are exempt from the yoke of slaver-
 which presses leavily upon nearly all the other tribes. In the C ami;.
 bodian language Al. Janneau thinks he call trace evidence of
 identity with many of the piiimnitive forms of the roots of the
 mother-tongue of the I nmlo- 1Juropean languages. The Aryan name
 " Saina)" appears among the ancientt regal titlcs of ( aiblwdlia,
 and while the Sanscrit *" lRanlayana " includes the Cambudiamis
amnongst the offsprimi, (tI the immaculate cow, ( abala, the
people tbeniselvts lave  1- om   the most remote antiquity
made the towv the object of sccial aduration.-Tlhie    S-
tion of the depopul.tion of certain d1ish 1ci, Inure e>-c.i.dly in
the Polynesian and othllr AustralAsiIn insular gioups, has lately
attracted especial attention among the members of the Anthro-
pological Society at Paris.  'Ihe Gambier Islands, which in
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