259 
relating to the sidereal part of the Heavens, 
we could be acquainted with every change that may happen 
in the nebulosity or in the magnitude of the stars which appa- 
rently compose them, their real union and construction must 
remain unknown. VVe can only hint, that every nebulosity 
which is carried into the region of a small patch of stars will 
probably be gradually arrested and absorbed by them, and 
that thus the. growth of stars may be continued. 
8. Of objects of an ambiguous constmction. 
From objects consisting decidedly of stars, but which either 
have nebulosity mixed with them, or are in such situations as 
to be seen in the same line with nebulosity, I proceed to give 
an account of some others, of which my observations have not 
ascertained into what order we ought to class them. 
It has been remarked, on a former occasion, that clusters 
of stars, when they are at a great distance, may assume a ne- 
bulous appearance.* This may be experienced by observing 
a certain celestial object with a telescope of an inferior space- 
penetrating power, through which it will be seen as a nebula; 
whereas with an instrument which has a higher degree of this 
power, its appearance will be a mixture of nebulosity and 
stars ; and if this power of the telescope is of a still higher 
order, the stars of the same object will then be distinctly per- 
ceived : the nebulosity will no longer be seen, and the object 
will be entitled^ to be placed into the rank of clusters of 
stars. 
Other objects there are, where a greater space-penetrating 
power will only increase the brightness of the nebulosity, and 
at the same time make the tinge of it more uniformly united 
Phil. Trans, for i8ii, page 270. 
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