f)F COMMON MATTER. 169 



struments, will not reach so far into the pro- 

 fundity of space, as to see more distant diffu- 

 sions of it ; and from the variety in the dim- 

 ness, faintness, and brilliancy of different bo- 

 dies, we may already surmise that the range of 

 the visibility of the nebulous matter, is confined to 

 very moderate limits ;" and, in order to enforce 

 this opinion, he repeats, at page 279, " that 

 the range of the visibility of nebulous mat- 

 ter, is what may be called very limited ; and 

 further observes, that it cannot be expect- 

 ed, that such nebulosities will remain visible, 

 when exceedingly farther from us than the 

 precise nebula ; the ratio of the known de- 

 crease of the light, will not admit of a great 

 range of visibility, within the narrow limits, 

 whereby this shining substance can affect th 

 eye ; and if our telescopes cannot be expected 

 to reach the nebulous matter, the actual quan- 

 tity of its diffusion may still farther exceed, 

 even the vast abundance of it already proved to 

 exist." 



It is impossible for me to mention the name 

 of HERSCHEL, without feelings of the greatest 

 respect. The Philosophical Transactions con- 

 tain a variety of papers from him, which 

 abound with a multitude of observations on 

 the construction of the heavenly bodies, and 

 of the quality of the matter of which they 

 are composed. In some of these papers, lie 



