1311.] accelerating (he Progress of Mineralogy. 125 



apophyllite under this last Dame in the collection of Secretary 

 Brandt, a collection unique lor old substances from the North, 

 which I purchased at Copenhagen some years ago. 1 even had a 

 keen discussion respecting this substance with M. Engestrom, who 

 ii:si>ted that it was a zeolite. This philosopher published an English 

 translation of Cronstedt's Mineralogy. He has likewise published a 

 good mineralogical guide through Sweden. All this takes nothing 

 from the merit of Andrada, who first made the substance known, 

 with characters sufficiently distinct to constitute a peculiar 

 species ; nor of the celebrated Iia.iy, who first determined its 

 crystallization. I hope one day to publish some details about 

 this rare mineral, which will serve to explain its position, and 

 the minerals that accompany it. These observations are the 

 fruits of my journey through Sweden, and of the researches 

 which I made on the spot. 1 likewise found in the same cabinet 

 a splendid specimen of botryolile, under the name of opakc 

 mamellar chalcedony, which the possessor considered as of so 

 little value that he had placed it among his duplicates. The 

 botryolile, since the substances from Arendal have attracted the 

 attention of naturalists, has likewise home the name of reddish 

 manganese, till Klaproth discovered in it silicious borate of lime. 

 It was this discovery that induced Ha'uy to make it a variety of 

 the species to which the Germans have given the name of datho- 

 lite, a species discovered by my countryman Esmark. 



Those persons who choose to occupy themselves with crvstal- 

 lography will likewise find sufficient materials to employ their 

 sagacity. Nature, though it acts after fixed principles, is nut- 

 withstanding inexhaustible. By observing and comparing we 

 shall continually find new varieties of form. We shall even 

 sometimes have the good fortune to discover the primitive form 

 of a substance, and thus prow by inspection what our illustrious 

 master, Ha'uy, predicts from calculation. 



The mineralogist even sometimes gets the start of the chemist 

 in the knowledge of the constituents of a mineral. lie predicts 

 from the crystalline form alone, and before he begins his experi- 

 ment, what the result of it ought to be. lie is induced to 

 recommence his analysis if his first attempt does not accord with 

 his prediction, and a more careful experiment at last brings the 

 chemist and mineralogist to agree. 



Chemistry alone, in my opinion, cannot serve as a basis for a 

 mineralogical system ; hut this does not prevent me from ac- 

 knowledging the great advantages which mineralogy lias drawn 

 from that science, and which she will continue always to draw 

 if she employ chemistry with prudence. Mineralogy has ad- 

 vanced only a- the art of analysing minerals advanced. 



The great progress of chemistry began in the North. The 

 names of Bergman and Scheele will always be placed at the head 

 of the philosophers who have changed the face of the science? a 

 science without the aid of which many manufactures would have 



