270 Dr. Herschel's Astronomical Observations 
that many things formerly taken for granted, should on exa- 
mination prove to be different from what ihey were generally, 
but incautiously, supposed to be. 
For instance, an equal scattering of the stars may be ad- 
mitted in certain calculations ; but when we examine the milky 
way, or the closely compressed clusters of stars, of which my 
catalogues have recorded so many instances, this supposed 
equality of scattering must be given up. We may also have 
surmised nebulae to be no other than clusters of stars disguised 
by their very great distance, but a longer experience and 
better acquaintance with the nature of nebulae, will not allow 
a general admission of such a principle, although undoubtedly 
a cluster of stars may assume a nebulous appearance when it 
is too remote for us to discern the stars of which it is com- 
posed. 
Impressed with an idea that nebulae properly speaking were 
clusters of stars, I used to call the nebulosity of which some 
were composed, when it was of a certain appearance, resolv- 
able; but when I perceived that additional light, so far from 
resolving these nebulae into stars, seemed to prove that their 
nebulosity was not different from what I had called milky, 
this conception was set aside as erroneous. In consequence of 
this, such nebulae as afterwards were suspected to consist of 
stars, or in which a few might be seen, were called easily re- 
solvable ; but even this expression must be received with cau- 
tion, because an object may not only contain stars, but also 
nebulosity not composed of them. 
It will be necessary to explain the spirit of the method of 
arranging the observed astronomical objects under considera- 
tion in such a manner, that one shall assist us to understand 
