ADVERTISEMENT. 



A LMOST four years have elapsed since this Essay 

 4~\. was announced to the public; and although a 

 considerable part of the manuscript was then ready, 

 yet, from a variety of considerations, I have been 

 induced to defer sending it to the press, and even 

 now the first part only of the Essay is laid before the 

 public. 



Among the motives which have operated most 

 powerfully to induce me to postpone the publication 

 of this work was a desire to make it as free of faults 

 as possible, and to accommodate it as much as possi- 

 ble to the actual state of opinions and practices in this 

 country. 



In proportion as my exertions to promote useful 

 improvements have been favourably received by the 

 public, and my writings have obtained an extensive 

 circulation, my anxiety has been increased to deserve 

 that confidence which is essential to my success. I feel 

 it to be more and more my duty to proceed slowly, and 

 to use every precaution in investigating the subjects 

 I have undertaken to treat, and in explaining what I 

 recommend, in order that others may not be led into 

 errors, either by mistakes in principle or inaccuracy in 

 description. 



