288 Miscellaneous Intelligenee. 
but on the area of spotted surface, as observed by Hofrath Schwabe; and 
we hope that by this means the periodicity will be represented with 
greater precision than before, and also that more light will be then thrown 
on the whole subject ; but in the meantime we would call the attention 
of all observers to the fact, that in the present state of our inquiries into 
the physical nature of the Sun and into the connexion of cosmical phe- 
nomena, even the most delicate changes observed deserve great attention, 
and that nothing should be overlooked by those who take an active inter- 
est in this problem.— Wot. Roy. Astron. Soc., xxvii, 286 
tion was about 40°, and it continued visible from four to five seconds. 
VY. MISCELLANEOUS SCIENTIFIC INTELLIGENCE. 
1, Researches on Gun-cotton.—Second memoir. On the Stability of 
Gun-cotton ; by F. A. Apet, F.RS., V.P.C.S. (From the Phil. we 
IV, xxxiii, 545, July, 1867, Supplement.)—The results of the many ° 
servations which had been instituted prior to 1860 upon the behavior of 
tions on the subject, as far as relates to the nature of the products ob 
tained at different stages of its decomposition, cannot t regarded as 
having a direct bearing upon the question of the stability of gun-cotton 
produced by strictly pursuing the system of manufacture prescri by 
von L inasmu it has been s ormerly 
experimented upon by different chemists varied very considerably 
composition, 
ae reeep ions recently published by Pélouze and Maury* 00 - 
sition of gun-eotton, and the influence exerted by light and h 
lig tts stability, are described as having been conducted with gun-eor 
