PREFACE. 



The eclectic character of my introductory volume, 

 which was intended to give a view of all the departments 

 of Mineralogy excepting Physiogra'phy, rendered it difficult 

 for persons employing it to avail themselves of other treatises 

 for full descriptions of the species- The inapplicability was 

 principally owing to my adoption of the improvements of 

 MOHS in relation to simple and compound varieties and to 

 the numerical scale for expressing the hardness, and to my 

 following BROOKE in the treatment of the regular forms'; 

 not to mention the circumstance, that my artificial tables 

 enumerated a mrnber of species whose descriptions had 

 not found their way into any English work. This was 

 foreseen in the preparation of that volume ; and notice was 

 accordingly given in it, that a second part, devoted exclu- 

 sively to descriptions, and constructed in accordance with 

 the principles of the first, was in preparation. 



In addition to the desire of supplying what was thus 

 wanting to carry out the plan of study which had appear- 

 ed to me to possess the greatest advantages, I was stimula- 

 ted to the attempt, in the hope of being able to contribute 

 something towards the more satisfactory determination of 

 American localities; an undertaking for which my rniner- 

 alogical travels had afforded me considerable facilities- In- 

 deed, so numerous had been the discoveries in important 

 mineral depositories since the last edition of CLEAVELAND'S 



B 



