MEMOIR OF HATJY. 381 



nearly all cases the decrements, by which the secondary planes are pro- 

 duced, were found to exhibit the simple proportions which nature 

 seems to have established in all the relations of number. Without 

 further hesitation might Haiiy now, for the third time, exclaim — all 

 is clear ; and at this stage only of his discoveries did he feel confidence 

 enough to speak of them to Daubenton, the master whose lessons he 

 had hitherto followed in modest silence. We may judge in what 

 manner they were received from the fact that Laplace, to wliom they 

 were communicated by Daubenton, and who at once foresaw their con- 

 sequences, lost no time in pressing the author to come forward and 

 present them to the Academy. 



This it was not so easy to induce him to do. To the worthy pro- 

 fessor of the College Lemoine the Academy was a terra incognita at 

 which his diffidence took alarm. Its usages were so little known to 

 him that he at first presented himself in the long robe which ancient 

 canons of the church are said to prescribe, but which no ecclesiastic 

 has for a long time worn in society except on strictly professional occa- 

 sions. Certain friends were apprehensive that, at a period of so much 

 levity, this robe might occasion a loss of votes; but to induce so scru- 

 pulous a casuist to quit it, nothing less was necessary than an appeal to 

 the advice of a doctor of the Sorbonne. "The ancient canons of the 

 church," said this wise referee, "are no doubt highly respectable, but 

 what is of consequence at this moment is, that you should belong to 

 the Academy." We are at liberty, however, to believe that the pre- 

 caution was superfluous, and that he would have been received, no 

 matter in what vestments he had presented himself. So emulous, in- 

 deed, was the Academy of such an acquisition that, without waiting 

 for the vacancy of a place in physics or mineralogy, one in botany, 

 which circumstances had rendered disposable, was conferred on him 

 with nearly entire unanimity, and even in preference to learned 

 botanists. 



A still more flattering proof of the regard of his new colleagues was, 

 that, by several of the most distinguished among them, he was pressed 

 to give a course of lectures and demonstrations in elucidation of 

 his theory. Lagrange, Lavoisier, Laplace, Fourcroy, Berthollet, and 

 Morveau might have been seen repairing to the College Lemoine to 

 attend the lessons of the modest professor, whom we may well suppose 

 confounded at finding himself become a master where he would have 

 scarcely presumed to call himself a disciple. But in a doctrine so 

 new, yet already nearly complete, the most skillful could be but learn- 

 ers. Never, perhaps, had a theory of the same extent been presented 

 in the same state of clearness and development from its very origin as 

 that of Haiiy, who had invented even the required methods of calcu- 

 lation, and had represented in advance, by formulas of his own, all the 

 possible combinations of crystallography. 



From no instance more clearly than from this may we learn to dis- 

 tinguish between the solid labors of genius, on which imperishable 

 structures are reared, and the ideas, more or less happy, which present 

 themselves for a moment to certain minds, but, for want of being elab- 

 orated, produce no durable results. 



Six or seven years before Haiiy, Gahn, a young Swedish chemist, 



