

Fan. 5, 1871] 
NATURE 
197 

| 
very striking, the whole sky becoming of a lurid | 
purple and very dark. The birds were hushed and 
frightened, and the charcoal burners’ fires in the moun- 
tains, some five miles distant were plainly visible.” 
At Oran the weather appears to have been still more 
unpropitious than at the European stations. For the 
observations with the spectroscope, this section of the 
Expedition was provided witha 6-inch equatorial, of eight 
feet focal length, by Cooke, of York, lent by the Royal 
Observatory at Greenwich, to which was adapted an ex- 
tremely ingenious recording spectroscope, the invention of 
Dr. Hugzins, who himself observed with it ; the manage- 
ment of the telescope devolving upon Captain Noble. 
A second smaller instrument, of 4 inches aperture, with 
a somewhat similar recording apparatus, was entrusted to 
Mr. W. Crookes, F.R.S., the Rev. F. Howlett attending to 
the telescope itself. The polariscopic observations were 
undertaken by Captain Salmond, R.E., and Lieutenant 
Collins, R.E. ; the instrument of the former being attached 
to a telescope of about thirty inches focal length and 2} 
inches aperture ; that of the latter to another of 6 inches 
aperture. General observations, sketching of the corona, 
&c., were to have been made by Mr. Carpenter, of 
Greenwich Observatory, with an exquisite 3-in. Dolland 
equatorial ; by Mr. Hunter, with a 4-in. of rougher con- 
struction ; by Lieut. Wharton, R.N., of the Urgent, with 
a 2? achromatic, mounted temporarily equatorially ; by 
Admiral Ommaney, with a small table telescope ; by Lieut. 
Ommaney, R.E,, with a binocular field-glass, on cards 
arranged for the purpose; and by the ship’s officers 
generally, with such telescopes as they could command. 
‘The 6-in. and 4-in. equatorials were erected under a tent ; 
the rest were employed more or less in the open air. 
Prof. Tyndall had established himself on a neighbouring 
fort, some 500 or 600 yards from the rest of the party, 
with a5-in. telescope by Dallmeyer, which had been used 
by Mr, Dela Rue at the Total Eclipse in Spain. His 
observations were to be of a general character. 
The atmospheric conditions in Oran in December are 
exceedingly like those of a very wet and windy English 
autumn, the day of entering into port having been the 
only moderately fine one experienced at all. The wind 
particularly was tremendous. On the 2Ist the observatory 
tent was blown down, and it was only by great ex- 
ertions that the instruments themselves were saved from 
destruction, 
The morning of the 22nd broke very doubtfully, heavy 
driving clouds obscuring the sun. The party were, how- 
ever, all at their posts betimes, and arranged their various 
instruments long before the predicted instant of first con- 
tact. The clouds obscured the sun at this particular time ; 
but soon, through a rift in them, the dark limb of the 
moon was seen encroaching on the sun’s disc. Ob- 
servation after this became very trying, as it was only 
possible at distant intervals to glimpse the progress of 
the moon, as she gradually advanced in her path. Spec- 
troscopic observation, or even polariscopic observation, | 
was practically impossible. Finally a glimpse was caught 
of the sun some eight or nine minutes before totality asa 
very thin crescent, and then every chink and cranny in the 
clouds closed up, and one dense and impenetrable pall 
covered the earth. Nothing remained now but to go out 
of the tent and observe the effect in the open air. It was 
certainly very striking. As the moment of totality ap- 
proached, the western sky turned of an awful livid purple, 
the clouds over head assuming a black tint. As the 
shadow swept over the earth, the eastern sky became 
obscured, while the western horizon lighted up like the 
grey dawn of a dull autumn morning. At no time, how- 
ever, during the totality, was it difficult to see the seconds 
on the face of a watch. The light was that of a cloudy 
evening, about an hour after sunset. One curious effect 
was observed, the apparent contraction or closing in of 
the celestial vault. Speedily, however, the dawn in the 

western horizon spread over the heavens ; but the sun did 
notreappearagain forat least half anhour after totality. M. 
Janssen, the French astronomer, who escaped, at the risk 
of his life, with his instruments in a balloon from Paris 
was stationed on a mountain some seven miles from Oran. 
He can have seen nothing whatever of the phenomenon 
which he had braved so much to observe. 
Another account from the same station states that the 
earlier stages of the Eclipse were seen and a photograph 
taken, but ten minutes before totality a dense bank of 
clouds came over the sun, which extinguished all hope 
and rendered useless the laborious preparations of many 
weeks. M. Janssen was of course equally unsuccessful. 
Though the darkness was almost appalling as it rapidly 
increased up to the moment of totality, still the scene 
was deprived of a large part of its impressiveness by the 
dense mantle of cloud which concealed nearly the whole 
heavens, 


SOCIETIES AND ACADEMIES 
LonpDon 
Chemical Society, December 15.—Prof. Frankland, F.R.S., 
Vice-president, in the chair.—The following gentlemen were 
elected Fellows :—P. T. Atkinson, R. Koma, J. F. Stark. Mr. 
Perkin, F.R.S., read a paper ‘‘On some new Derivations of 
Coumarin.” The author succeeded in obtaining the following 
new bodies :— 
Dibromide of Coumarin C, H, O;- Er, 
Dichloride of Coumarin Gon eda OF 0 TH 
@ Bromocoumarin ~ =~. 3. . Cy He Br Oy 
” ” 9. ise eee eet ” 
e@Ghloraconmann' (eee «ane <p CaidleaGli@s= 
” ” Oa Ji iC . ” 
a Dibromocoumarin ... . C, H, Br, O, 
B 2” ca ¢ 2 ” 
Tetrachlorocoumarin . Sy rk (lap 
Gonmanilicfacidly yy ca cree es el Ggeelea@s 
Bromocoumaric acid C, H; Br O, 
Sulphocoumaric acid . . Cy Eg One SOS 
Disulphocoumarie acid 2G AC aNEls 03: 250; 
Dibromide of Coumarin.—A solution of coumarin in carbon di- 
sulphide is mixed witha similar solution of bromine, and the 
mixture, after leaving it to stand for twelve hours, allowed to 
evaporate spontaneously. When dibromide of coumarin is 
treated with an alcoholic solution of potassic iodide it becomes 
brown, and on evaporation deposits needles apparently consisting 
of a mixture of iodine and coumarin crystals, a Bromocoumarin. 
A simple process for the preparation of Bromocoumarin is to de- 
compose the dibromide of coumarin with alkalis, the following 
reaction taking place :— 
C, H, O, Br, + KHO = C, H; Br O, + K Br + H, O 
at . bes, 

Dibromide of coumarin. Bromocoumarin. 
a Bromocoumarin, when left in contact with cold alcoholic am- 
monia, decomposes with formation of ammonic bromide, and a 
non-crystalline sticky mass easy soluble in water. Heated with 
potassic hydrate it yields potassie bromide and a new acid. a 
Dibromocoumarin.—At a previous occasion Mr Perkin prepared 
this body by heating in a sealed tube to 140° C. a mixture of one 
part of coumarin, two parts of bromine, and four or five parts 
of disulphide of carbon. He since found, however, that this 
process is greatly improved by the addition of iodine to the 
mixture, as it is then only necessary to heat the sealed tube for 
four or five hours in a bath of salt and water to complete the 
reaction. The fusing point of this substance is 183° C. and not 
174° C. as had been previously given. $8 Bromocoumarin.—The 
hydride of sodium bromosalicyl when submitted to the action of 
acetic anhydride, yields a quantity of hydride of bromosalicyl 
and a body which, when crystallised from alcohol, yields colour- 
less flat prisms, theanalysis of which showed it to be monobromo- 
coumarin, Cs H; Br O,. It greatly differs in properties from 
the bromocoumarin previously described, its fusing point being 
160°C., or 50° higher, and when boiled with alcoholic or aqueous 
potassic hydrate it does not decompose with formation of potassic 
bromide, but simply dissolves like ordinary coumarin. B Dibromo- 
coumarin.—On treating the hydride of sodium ad/bromosalicyl 
