8 Biographical Notice of the Abbt Haiiy. 



in the University of Glasgow, was, so far as we know, the 

 first who seems to have studied and appreciated the labours 

 of our author, and in his conversation, his lectures, and his writ- 

 ings, he was, no doubt, the means of making his countrymen 

 acquainted with the crystallographic system.* 



" See the Article Crystallography drawn up by Dr Thomson for 

 the Edinburgh Encyclopaedia, and his System of Chemistry, 5th Edition, 

 vol. iii. p. 125. Mr Tilloch, so early as 1798, reprinted the sketch which 

 Haiiy had given of his theory in the Annules de Chimie, vol. xvii. 



In speaking thus highly of the works of Haiiy, we have no design of 

 depreciating the previous labours of Rome de l'lsle, and we think it right 

 to add the following estimate of his merits, drawn up by an eminent Crys- 

 tallographer, as an addition to the life of Rome de l'lsle in the Edinburgh 

 Enct/c/opcedia, vol. xvii. Part ii. which is on the eve of publication. 



The great merits of Rome de l'lsle in mineralogy are less generally ac- 

 knowledged than they deserve ; particularly by the French mineralogists. 

 Modern mineralogists are often astonished at the accuracy of the descrip- 

 tions given by this author, even of such substances as were afterwards con- 

 founded with each other by Haiiy and those who copied him. In almost 

 every page his power of observation is displayed in a remarkable degree, 

 joined with good sense, correct reasoning, and vast mineralogical erudi- 

 tion. His figures of crystals, indeed, are frequently far from affording 

 the pleasing effect of geometrical perfection, which captivates the eye in 

 the figures adorning the great work of Haiiy ; yet they betray the hand 

 of the master, who seized the peculiar character of the individual crystals 

 which he represents, and which is often better preserved in these sketches 

 than in better executed drawings. 



The student will always find a great deal of instruction in perusing the 

 second edition of his Crystalhgraphie, the result of more than twenty 

 years continued and well-directed exertions ; but those who are already 

 proficient in the science will find pleasure in discovering in his writings 

 that they have often been anticipated in their descriptions. It may be 

 said, with perfect propriety, that, however ingenious the views of Haiiy 

 may have been in regard to the property of cleavage, he could never have 

 succeeded in establishing them as a general system, applicable to all crys- 

 tallized minerals, had he not possessed the observations and drawings of 

 Rome de l'lsle. This great man met with all the opposition commonly 

 incidental to new ideas, or to a degree of accuracy which, in fact, is fin- 

 beyond what had been customary before; but the predjudices had worn 

 off, when Haiiy's system appeared, which then earned the rewards both 

 of its own merits and of Rome de l'lsle's. Haiiy has always been candid 

 enough to acknowledge every thing he owed to the latter ; he supplied 

 the link which made Rome de l'lsle's observations useful, by introducing 

 general views in crystallography, founded upon geometrical processes, and 

 by giving a particular name to every substance determined as a particular 



