Chemistry and Physics. 55 
In the same article I have stated that the photographs, taken 
by the American party in Spain, appear to differ essentially 
fessor Winlock and myself, between a copy of the American 
photograph and a drawing* of Mr. Brothers’ photograph, which 
(drawing) he had himself sent to Mr. Lockyer. 
ere was a general and even striking agreement between 
the two in respect to the position of the ‘gaps’ and the distri- 
bution of the luminosity, yet there certainly were, as Mr 
pointed out, very noticeable and important differences, and of 
a character to suggest that the extensive outside radiance might 
probably be of a less permanent character than the leucosphere, 
and of a different origin. 
But I understand that when photographic copies of Mr. 
Brothers’ and the American negatives are made to a common 
scale then these differences disappear and the agreement becomes 
nearly absolute in respect to all essential particulars. If this be 
so, it certainly bears very strongly in favor of those theories 
which assign a purely solar origin to the whole phenomenon. 
Dartmouth College, May 10, 1871. 
SCIENTIFIC INTELLIGENCE. 
IL CHEMISTRY AND PHYSICS. 
1 M y 
Ph.D., Assistant in the University laboratory, Tibingen, Germany. 
—In my former note, (volume i, page 462), I stated that when or- 
tassium salt that had been made use of for the first exper- 
: c : is was accomplished 
red an ac 
izing with carbonate of barium, dividing the solution into two 
equal parts, precipitating the barium from the one exactly with 
‘Sulphuric acid and then mixing the two again. On evaporating 
this solution, it became filled with beautiful needles on cooling. 
*TIam not sure but we had a photographic copy of Mr. Brothers’ drawi a 
fad of the drawing itself; but we did not have a photographic copy of the 
original negative. No such copies had then been made, 
oe 
ee 
Pigs 
