[ * x ] 



not belong to them, o f her collections will be 

 •augmented ; and thus every thing will be 

 brought into a due order. If feme colledors 

 fbculd not immediately be able to comprehend 

 this Syftem or Clarification, it cannot much 

 detriment the fcience; and it is likewife of very 

 little cenfequence in proportion to the advan- 

 tage that will accrue to the ftudv by this me- 

 thod, the more it {hall be cultivated and 

 improved. 



Ptolemy cannot be fnppofed to have known 

 the value of every book he fent to his great li- 

 brary in Alexandria, and he had doubtlefs no 

 time to clals them himfeif according to the con- 

 tents of the different bocks acquired ; however, 

 his love for collecting mbfft have continued during 

 his life : Moreover, the advantages obtainable 

 from it would have been afterwards difcovered, 

 had it not been difecried ; or, as fomctimes 

 happens, had not the collection been fuppefed 

 to gain feme additional value by being made 

 difficult of accefs to the learned. 



As feen as we are arrived to fuch a pitch, as 

 by the examination of a mineral body to dis- 

 cover or know all its constituent parts, and can 

 affert with certainty that it can be no further 

 decompounded by any method hitherto known ; 

 then fuch a body ought, according to the in- 

 tention of this Effay, to receive its fpecific 

 name, and not before j for otherwife it will 

 be vague and trivial. However, I have not 

 aflumed a confidence to do this even with fuch 

 piineral bodies that I in fome reipeel can aver 



1 pretty 



