Prof. Norton on the Dimensions of Donati’s Comet. 383 
Wutrestre [p. 349, Il, V]—The massive wulfenite from Garmisch, is a mixture 
of molybdate of lead, with carbonate of lead a _ oo substances, as shown by 
Wittstein’s analysis (Kopp’s Jahresbericht, 1858, 72 
Pb Oa Mg Fe Mo- Si ig gh boreal 
$38 1085 «357 «280-2000 , 1620 004 
Ziso-Bioom [p. 460, 518, VII].—Dr. a a ee hag a — carbon- 
ate of zine from Marion Cou unty, Arkansas, as a ecies under the name ma- 
rionite Sahay Geol. Rep. mapas. p- 153). The catilael composition he found : 
Zn 6 H ‘ 
73°26 i501 1181 = 10008 
[This is identical with analyses 1a, of zince-bloom from Santander in Spain, by Pe- 
terson and Voit, api in the last supplement. This analysis gave Zn 73°1, 
6161,H118. These a alysts found that zine-bloom undergoes a change on ex- 
posure to the air, thereby losing both carbonic acid and water. A specimen of 
la, exposed to the air for three months was found to contain Zn 74°78, 6 18°81, 
H1145. Other er haag by Braun are quoted in the last supplement. Peterson 
and Voit (Aun, d. Chem. u, Pharm., eviii, 50) ae Ee formula for zinc-bloom Zns, 
erreil acre the occurrence of zinc-bloom at Santander in oolitic 
47). 
(Unstitut, No, 1 
Art. XXXIV.— Theoretical by Brot Wd x Lee Ee of 
Donati’s Comet ; f, W. A. Ni 
ion. Resuming the equation of the approximate or orbit of 
“gle emitted from the nucleus, obtained in the investigation 
u 
a oe ee ln 
ne eet Fe ea a tl 
ksina pr kcosa” 
a which the axis of z coincides with the original direction of 
on, a denotes the angle of inclination of oe initial line of 
2 prod let us to a new 
Pp sonal by the sun’s puso lee ee 
Neident with the radius-vector ee the orbit of the comet. 
iting the transformation of codrdinates, reducing, and denot- 
