96 
time have been united together and formed a single deposit, 
and shows how that excludes the hypotheses that they w2re 
formed in the place where they are now found, and that they are 
derived from deposits anterior to the period of volcanic activity. 
—On the relations between the maxima and minima of the solar 
protuberances, and the maxima and minima of the diurnal 
oscillation of the declination magnet. Prof. Tacchini, after 
giving an account of his own researches already published, on 
the maxima and minima of the sunspots and solar protuberances, 
referred to the observations of Prof. Schiapparellion the values 
of the range of diurnal oscillation of the declination needle, and 
from the comparison of the two sets of observations, it appears 
that of late years the connection between the solar protuberances 
and terrestrial magnetism is more strikingly manifest. These 
and other similar observations, Prof. Tacchini added, corroborate 
the idea entertained by himself and some others, that electricity 
plays the chief part in the solar protuberances, and that electri- 
city is able to produce corresponding magnetic disturbances on 
our globe. It may therefore be inferred with certainty that the 
phenomena of the sunspots, the solar protuberances, and terres- 
trial magnetism are closely connected together, and that by means 
of one of these sets of phenomena it is possible to determine 
with tolerable precision the epoch of the othertwo. In dealing, 
however, with phenomena of rather long period continuous 
observations for at least half a century are necessary to make 
our researches complete.—On the spectroscopic observations of 
the limb of the sun and the solar protuberances made in 1881 
and 1884 at the Royal Observatory of the Capitol.—Prof. 
Respighi laid before the meeting some considerations of his 
own, based on observations made in his own observatory, and 
jeading him to conclusions different from those of Prof. Tacchini. 
He maintains that the maximum of solar protuberances oc- 
curred towards the end of the third quarter of 1881. Holding 
that the sun-spots are due to partial cooling of the surface of the 
sun, and the protuberances to the escape of gases from the in- 
terior, Prof. Respighi believes that such perturbations are not of 
a nature to occur in periods, even though they retain a certain 
relation among themselves, and still less can he admit any con- 
nection between the maxima of the solar protuberances and the 
elements of terrestrial magnetism.—Meteorological observations 
made by Signor P. Orlandi, a physician of Rome, during the 
years 1809-1820. Signor Narducci called attention to a manu- 
script in the Biblioteca Angelica, containing some interesting 
medico-meteorological observations made by Signor Orlandi, a 
medical man belonging to Rome, between the years 1809 and 
1820. These observations are copious and complete, having 
been made daily. They also include notices of movements of 
the earth’s crust and inundations of the Tiber. Signor Narducci 
mentioned that Dr. Orlandi was a maa of science and writer of 
great renown inhis time. Large extracts from the observations of 
Orlandi are to be published in the Ava/s of the Central Office of 
Meteorology, and they will thus be able to be compared with those 
published by distinguished astronomers belonging to the same 
epoch.—On the last and recent maximum of sun-spots and solar 
protuberances. Prof. Riccd gave an account of his own observa- 
tions made at Palermo on the phenomenon of the solar pro- 
tuberances, which was so important on account of its coincidence 
in time with very singular manifestations of the solar macule. 
Prof, Riccd deduced from his own observations, harmonising, 
as they do, with those of Prof. Tacchini, that, starting from the 
last maximum in the period of eleven years, the number of the 
protuberances went on increasing till 1881, when a first maxi- 
mum occurred. It was further verified that the absolute maxi- 
mum fell between the end of 1803 and the beginning of 1804, 
and that on that occasion the maximum of protuberances con- 
tinued beyond that of the suu-spots. Finally, leaving out of 
account Secondary oscillations, Prof. Riccd asserted that a 
parallelism may be observed between the frequency of sun-spots 
and protuberances, the principal maxima and minima of both 
phenomena coinciding with one another.—On the relation 
between the maxima and minima of the sun-spots and the 
maxima and minima of the diurnal variations of the declination 
needle observed at Genoa. Prof. Garibaldi has made a com- 
parison between the normal compensated series of groups of 
sun-spots observed by Prof. Tacchini during the period 1877-84 
and the series of diurnal variations of the declination needle 
observed at Genoa during the same period. From the mirror- 
tracings of the author it appears that the two series agree per- 
fectly. Hence, considering that the observation of the sun and 
its spots depends upon the clearness of the sky, while the mag- 
NATURE . 
| May 28, 1885 
netic influence of the sun can always act, and observations ot 
magnetic changes can always be easily made, Prof. Garibaldi 
arrives at the conclusion that the epochs of maxima and minima 
of the sun-spots may be inferred from the indications of the 
declination needle when direct observations are not obtainable. — 
Action of nascent hydrogen on methyl-pyrrol. Drs. Ciamician 
and Magnachi having already ascertained by previous researches 
that pyrrol is converted into an alkaloid called Ayrrodim under 
the action of nascent hydrogen, communicated a preliminary 
notice of the experiments commenced by them with the view of 
increasing the number of bodies belonging to the pyrrolin series, 
experiments in which they studied the action of nascent 
hydrogen on other derivatives of pyrrol.—On a method for the 
electric calibration of a metallic wire. Dr. Ascoli, pointing out 
that in accurate measurements it cannot be assumed that the 
length and resistance of a wire stand in a constant relation to 
one another, described a very simple and easily applied method 
of his own by means of which a wire can be quickly and per- 
fectly calibrated without the aid of special instruments and with- 
out accessory measurements. By the consti7ction of a curve 
the resistance of the corresponding piece of wire is obtained 
from the area limited by the curve.—Other communications : 
Prof. Besso presented a first note on a class of differential linear 
equations of the fourth order and on the equation of the fifth 
degree.—Prof. Gomes-Teixeira furnished a paper on the deter- 
mination of the algebraic part of the integral of rational 
functions.—Prof. Ricco made a preliminary note on the observa- 
tions made by him on red glows.—Dr. de Franchis offered 
various considerations on some relations between the velocities 
| of efflux, the specific heats, and the mean squares of the 
molecular velocities of gases. 
“CONTENTS 
PAGE 
Practical Instruction in Botany: . . - 2 2s 0.s-wo 
The Pennatulida of the Norwegian North Atlantic 
Expedition. By Prof. H.N. Moseley, F.R.S. .. 74 
Our Book Shelf :— 
Baker’s ‘‘ Flora of the English Lake District” . . . 75 
Mott’s ‘Fallacy of the Present Theory of Sound.”— 
Dr, W.H.Stone ue. 2 22 ee 
Schréter’s ‘‘ Kryptogamen-Flora von Schlesien” . . 76 
Letters to the Editor :— 
On the Terminology of the Mathematical Theory of 
Elasticity. W. J. Ibbetson. . . . . =... - = 76 
The Colours of Arctic and Alpine Animals. —Lorenzo 
Camerano .. 77 
On Certain Stages of Ocular A fter-Images.—H. Frank 
Newall ss. aS. ew a Ve 
‘* Speed” and ‘‘Velocity.".—Senex. ....... 78 
The Male Sole is not Unknown.—Francis Day .. 78 
The Aurora of March 15, 1885.—Prof. E.E. Barnard 78 
Catalogue of Fossil Mammalia in the British Museum, 
Part 1.—The‘Reviewer. = ) 2 5.) 
The Orchid Exhibition’ . 2 3) 25 20) eee 
Wheat-Production in India. By Prof. John Wright- 
Sonwy ae 79 
The Reports of the United States Commission of 
Fish and Fisheries tor 1881 and 1882. By J. T. 
Cunningham . 6 Jie Ji 2 6 «5 > 5 ee 
Notes: = << dostecile slosre is) wie: sale sien 
Our Astronomical Column :— 
Double:Star Measures . . . « + «-+ «01 MeeEOG 
Minima of Algo) ... .- suid. sign oe 
Central Solar Eclipses in New Zealand. ...... 86 
The Daylight Occultation of Aldebaran on May 22, 
1868. ve ate Sha ee Bee, a 
Astronomical Phenomena for the Week 1885, ; 
May 31to June'6 . . 2 45 |e hero ie) oll eee 
Chemical Notes:«<.:. <4: $i. i.) Secu eeememenen 
Geographical Notes... .. 2. s+ ess eee 
A Yearly and a Daily Period in Telegraphic Per- 
turbations. By Dr. Sophus Tromholt. (Zilustrated) 88 
A Note relating to the History of the Aurora 
Borealis. By Dr. Sophus Tromholt.......+ 89 
University and Educational Intelligence ..... 90 
Scientific Serials| |... 2% St) a0) cia. a ee 
Societies and Academies .....+.++-+++- QF 
