MEMOIR OF HAUY. 379 



prepared a herbarium with unusual care and neatness, and even invented 

 processes by which the color of his flowers has been preserved to the 

 present day.* Here he took his first lesson in the right use and aims 

 of method, and by frequenting the '• Jardin du Eoi," which was near 

 his college, he extended his ideas and exercised himself more and more 

 in the work of classification and comparison. 



Happening one day to join the crowd which at that time attended 

 the lessons on mineralogy given by Daubenton in the " Jardin du Roi," 

 he unexpectedly found himself in the presence of a new object of study, 

 more congenial to his first taste for physics than even that of plants. 

 Numerous, however, as was the attendance on Daubenton's lessons, 

 it was mainly of such auditors as left botany and mineralogy where 

 they found them. Having come earlier to the study, they might know 

 more of both than Haiiy ; but custom itself, in familiarizing them with 

 the difficulties of those sciences, had caused them to disappear. To 

 Haiiy, who came later, these difficulties presented themselves after a 

 different manner. The contrarieties and gaps in the series of ideas 

 strongly arrested the attention of a vigorous thinker, who, in the 

 height of his powers, approached for the first time a new object of 

 study. If the constancy observable in the complicated forms of flowers 

 and fruits, and all the parts of organized bodies, affected him with 

 admiration and wonder, how is it, he might ask, that the forms of 

 minerals, so much more simple and even geometric, are not subjected to 

 similar laws? for, at that time, even the partial and imperfect rela- 

 tionship proposed by Rome Delisle, in the second edition of his Crys- 

 tallography, was unknown. How is it, might Haiiy say, that the 

 same stone, the same salt, show themselves in cubes, in prisms, in 

 needles, without the change of an atom in their composition ; while 

 the rose has always the same petals, the acorn the same curvature, the 

 cedar the same height and the same development? 



While absorbed in these ideas, it chanced that in examining some 

 minerals at the house of a friend, he was so fortunately awkward as 

 to let fall a beautiful group of calcareous spar crystallized in prisms. 

 One of these prisms broke in such a way as to exhibit at the point of 

 fracture planes not less smooth than the original surface, but present- 

 ing the appearance of a new crystal, wholly different in form from the 

 prism. Haiiy observes this fact, and attentively examines the planes 

 and angles of the fragment. To his great surprise, he finds that they 

 are the same with those of Iceland spar crystallized in rhomboids. He 

 returns to his own cabinet, selects a specimen crystallized in the form 

 of a six-sided pyramid, such as is usually called dog tooth spar, and 

 breaking it, sees the same rhomboid of the Iceland spar emerge; the 

 splinters which fall are themselves smaller rhomboids. He tries a third 

 spar, called from its form lenticular, and still it is the rhomboid which 

 discloses itself in the center, and smaller rhomboids detach themselves 

 in the fragments. 



He might well exclaim, all is clear; the particles of calcareous spar 

 have but one and the same form: it is only in grouping themselves 



* See his " maimer of forming herbariums, " in the Memoirs of the Academy for 1785, page 

 210. 



