352 , Miscellanies. 



compass as possible, consistently with their being Intelligible ; and 

 yet embracing the most important things : copious references are also 

 giv^en to elementary and original writers, that the student may, if he 

 can find the time and the books, prosecute the subjects farther. I 

 have endeavored to avoid scattering the different members of a sub- 

 ject into separate parts of the volume, and have aimed as far as the 

 previous statements in the work, or the actual state of general knowl- 

 edge would permit, to keep entire subjects together. 



Few authors, after incurring the great expense of time and money, 

 and toiling through the severe labor, required by a difficult work, are 

 either disposed or able to encounter the hazards of publication. The 

 present, like most other works, has therefore, been consigned to the 

 bookseller. Those, into whose hands it may pass, have a right to 

 know the reasons that have determined the mode of arrangement and 

 execution. This exposition, partially sketched in the plan, and at 

 the heads of some of the secdons, it was always my intention to give, 

 more fully, when the work should be finished, and I am the moreover 

 impelled to fulfill my design, by a respectful courtesy to those Col- 

 leges and Insdtutions which, after examining the first volume, have 

 already placed my work in their printed list of classical books, or 

 have communicated to me their intention so to do. 



It is proper to add, that although I have been assisted in the 

 revision, by several gentlemen, eminently qualified for the duty, and 

 obligingly attentive to it, some errors and omissions have been dis- 

 covered, since the sheets were printed. 1 alone am responsible for 

 them, and as far as they have appeared important, or the necessary 

 corrections were not very obvious, I have noted them in the errata 

 or addenda. I pretend not, however, to have stated every fact and 

 every opinion, for Chemistry has now become a vast Encyclopedia 

 of knowledge. While selecting the materials, through so boundless 

 a range, it is a matter of extreme difficulty to give even an out- 

 line, within moderate limits; and it is (as fully appears on a critical 

 examination of the best elementary works,) still more difficult to 

 avoid repetitions, necessary or casual, and to avoid also omissions, 

 as well as errors in fact or opinion, and discrepancies in both ; espe- 

 cially in a first edition of a work, demanding incessant vigilance, 

 and an extensive examination and comparison of original and ele- 

 mentary writers. 



Yale College, January 1, 1S31. 



