310 Dr. Herschel's Astronomical Observations 
Number 63 of the Connoissance des Temps is “ Avery 
bright nebula, extending from north-preceding to south- 
“ following g or 10' long, and near 4/ broad ; it has a very 
“ brilliant nucleus.” Fig. 27. 
I. 107 is “ A very bright round nebula, about if minutes 
“ in diameter ; it has a bright nucleus in the middle/' Fig. 28. 
The nuclei of these nebulae, after what has been proved, of 
the existence of a condensing power, I need not hesitate to 
ascribe to the longer continuance of its action, which appears 
to bring on a consolidation ; and that this may be the conse- 
quence we may conclude, not only from the power of con- 
densing, which argues a sufficient quantity of matter, but also 
from the quality of shining ; for this proves that the substance 
which throws out the nebulous light is endowed with some other 
of the general qualities of matter besides that of gravitation. 
A second remark I have to make is, that the opaque nature 
of the nebulous matter which was before inferred from ana- 
logy, is here supported by observation ; for these consolidated 
nuclei have a considerable resemblance to the disks of planets ; 
and if this matter consisted only of a luminous substance, the 
increase of light would probably far exceed their observed 
lustre : this being the case, the power of arresting light in its 
passage is an additional quality, very different from those 
which have already been mentioned, and seems to be analo- 
gous to properties which we know to belong to hard and 
solid bodies. 
2 6. Of extended Nebula that shew the Progress of Condensation. 
When the nebulous matter is much extended in length, it 
appears from the following nebulas, that with those which 
