Biographical Notice of the Abbe Haiti/. 3 



agreeable and useful to his friend. At the first herborization, 

 he could name the plants, and assign them their botanical 

 characters ; very soon he was on a level with his companion 

 and from that time every thing was common between them, 

 even to their amusements. 



The College of Cardinal Lemoine is near the Garden of 

 P'ants; and it was natural that Haiiy should often choose it 

 for his promenade. Seeing one day a crowd of auditors press- 

 ing in to the attendance of a lecture of Daubenton, on mi- 

 neralogy, he wished to hear this professor, and was charmed 

 to find, in this part of natural history, subjects of theory 

 more analogous to his taste for the physical sciences, .nan the 

 pursuits of botany. The comparison of these two varieties of 

 the productions of nature, excited in his mind a train of re- 

 flections which led the way to his discoveries in crystallogra- 

 phy. How is it, said he, that the same stones and the same 

 salts should show themselves in cubes, in prisms, in needles, 

 without the change of a single atom in their composition, 

 while the rose has always the same petals, the gland the same 

 flexure, the cedar the same height and developement ? He 

 was occupied with these ideas, when examining one day some 

 minerals at the house of hia friend M. Defiance, he awkward- 

 ly, though luckily, let fall a beautiful group of prismatic cry- 

 stals of calcareous spar. Some fragments broken from the 

 group, presented the appearance of a new and regularly form- 

 ed crystal, with smooth surfaces. Haiiy discovered, with Sbr- 

 prise, that this form was precisely that of rhomboidal crystals 

 of Iceland spar. " The mystery is explained,'" cried he. In 

 fact, his whole theory of crystallography, a monument as im- 

 perishable as the truths of geometry, is founded on this ob- 

 servation ; but because this discovery was ;:ltogether geometri- 

 cal, it was necessary that it should be explained and perfected 

 through the medium of geometry. Haiiy felt on this occa- 

 sion also, that his studies had been imperfect. But he was 

 not discouraged. He perceived what he stood in need of in 

 order to continue his researches upon the structure of cry- 

 stals ; invented a method of measuring and describing them, 

 and not till then did he venture to speak of his discoveries to 

 his master, to whose lessons he had modestly and silently at- 



