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relating to the Construction of the Heavens. 
In looking over this table, it may be noticed that I have in- 
serted several nebulosities that were only suspected. Had I 
been less scrupulous at the time of observation the word sus- 
pected would generally have been omitted ; for with this 
nebulosity, as well as with the great number of nebulas that 
in my catalogues are marked suspected, I have almost without 
exception found, in a second review, that the entertained sus- 
picion was either fully confirmed, or that, without having had 
any previous notice of the former observation, the same sus- 
picion was renewed when I came to the same place again. 
When these observations are examined with a view to im- 
prove our knowledge of the construction of the heavens, we 
see in the first place that extensive diffused nebulosity is ex- 
ceedingly great indeed ; for, the account of it, as stated in the 
table, is 151,7 square degrees; but this, it must be remembered, 
gives us by no means the real limits of it, neither in the paral- 
lel nor in the meridian ; moreover the dimensions in the table 
give only its superficial extent ; the depth or third dimension 
of it may be far beyond the reach of our telescopes ; and when 
these considerations together are added to what has been said 
in the foregoing article, it will be evident that the abundance 
of nebulous matter diffused through such an expansion of the 
heavens must exceed all imagination. 
By nebulous matter I mean to denote that substance, or 
rather those substances which give out light, whatsoever may 
be their nature, or of whatever different powers they may be 
possessed. 
Another remark of equal importance arises from the con- 
sideration of the observed nebulosities. By the account of the 
table we find that extreme faintness is predominant in most 
