'2 Biographical Account of J. G. Gahn. [July, 



engaged his young and eager spirit. He was one whose ardour, 

 while it bore him rapidly forward, did not permit him carelessly 

 to pass over any thing ; and that vivacity of disposition which 

 directed his attention to so many and various objects in rapid 

 succession, was but a guide to him, though it must have bewil- 

 dered others. He was one of the few who can run and read, 

 and turn to account, accidents, and even blunders, of the most 

 fortuitous description. 



Thus it happened to him, while yet a pupil in the Academy, 

 that a specimen of crystallized carbonate of lime dropped from 

 his fingers. It was of the variety which mineralogists term dog's- 

 tooth spar, and the fall shattered it into fragments. While 

 gathering these up, Gahn's attention was arrested by the 

 appearance which one of them presented, and in which a portion 

 of the original nucleus had been developed by the accident. 

 This hint, which another might have neglected or misunder- 

 stood, he immediately followed up ; nor did he rest satisfied 

 until he had extracted by cleavage the rhomboid which consti- 

 tutes the primitive form of this mineral, from a great variety of 

 its secondary crystals. Bergmann, to whom this observation 

 and discovery were communicated, published, immediately after- 

 wards, a Dissertation on the Forms of Crystals, which called 

 forth the well-merited admiration of men of science. But 

 while Bergmann reaped this honour from his Essay, he had 

 omitted to mention, that it was the discoveries of the pupil, which 

 had furnished the basis of all the reasonings of the master. 



The next important service which the subject of this memoir 

 rendered to science, was the investigation of the nature of the 

 earth of bones. In this discovery accident had no share ; yet 

 it too yielded the first-fruits of reputation to another than the 

 true owner. It is indeed to be regretted that in too many 

 instances, Gahn suffered others to claim and to enjoy the reputa- 

 tion of improvements which they had never made, and of merit 

 which they had never earned. In this he was so negligent dur- 

 ing his life, that, it is to be feared, many of his discoveries are 

 at this moment ascribed to others, and can now never be vindi- 

 cated for their real author. For this strange indifference to 

 fame, permitting others to reap where they had never sown, it 

 is not easv to account: though we have an instance of some- 

 thing similar in the conduct of another celebrated chemist, Dr. 

 Black, who, after finding the tract, and clearing the way, to a 

 most fascinating field of discovery, contented himself with sit- 

 ting down at the barrier which his genius had overthrown, while 

 others passed by, and gathered an easy harvest of reputation. 



Previously to this period, the earth of bones had been univer- 

 sally considered to be sui generis and peculiar. Gahu, however, 

 succeeded in analyzing it, and in establishing it to be a neutral 

 salt, composed of phosphoric acid and lime. This is a disco- 



