20 INTRODUCTION. 



The veil is withdrawn from the face of nature, and a constitution 

 of things, not at all suspected by those ignorant of chemistry, is un- 

 folded. 



The pupil in this science discovers that he has, all his life, walked 

 unconsciously amidst powerful, although unseen energies ; that like a 

 child scattering sparks among gun-powder, he has often heen sport- 

 ing with dangerous elements, and that, with all his curiosity and in- 

 telligence, he has known only the surface of things. He finds, eve- 

 ry where, innumerable applications of his knowledge to purposes of 

 practical utility, to those of domestic life, to the arts which enrich 

 and adorn society, and to the illustration of the wisdom, power and 

 goodness of that great being, whose pleasure called the physical uni- 

 verse into existence and constantly sustains it in order and beauty. 



To exhibit the proof of these statements, even in outline, would 

 require a distinct recital, and might well occupy a treatise ; but op- 

 portunities will occur in the progress of this work, when these truths 

 may be, to a certain degree, illustrated. 



It would be premature, to attempt, at this time, to exhibit the na- 

 ture of the evidence upon which chemical deductions are founded, 

 and the mode in which the study and exhibition of the science are 

 prosecuted. 



It is sufficient to say, that like the other physical sciences, chemis- 

 try derives its evidence, from experiment, and the observation of. facts ; 

 but, as a great proportion of the facts are such as do not occur in 

 common life, and still, as they all have their foundation in the consti- 

 tution of things, it becomes necessary for the philosophical chemist 

 to perform a great number of experiments ; in other words to exhibit 

 numerous facts ; for, an experiment is nothing but the exhibition of a 

 fact, happening according to natural laws, which it is not in our power 

 either to create, to cancel or to modify. Hence, the necessity of be- 

 coming well acquainted with those laws. Whenever all of them 

 shall be fully understood, then chemistry will have reached its perfec- 

 tion, and in relation to the science, the greatest service which we can 

 perform, is to extend and perfect its general laws. At some future 

 day, it will not be necessary to study facts so much in detail as now : 

 selections will be made to illustrate general principles, and thus chem- 

 istry will be assimilated to natural philosophy. 



Chemistry may be regarded in three views, all of which are inter- 

 esting and important. 



1 . As a branch of general philosophy. 



2. As a school for the chemical arts and for many of those of do*- 

 rnestic economy. 



3. As an important auxiliary to the profession of medicine and to 

 pharmacy. 



