Miscellanies, 4 05 



h. 100 models; the same as above, wilh 77 secondary forms, 

 $6,66, (16 J florins.) 



All the specimens of the different collections are well selected and 

 fresh, so as to be perfectly adapted for studying as well as teaching. 

 Each specimen is accompanied by a ticket, indicating the name of 

 the substance and the place where it is found. In case it is desired, 

 the labels will be given both in French and English. The collec- 

 tions, also, if it is wished, will be arranged according to any other con- 

 venient system. We can furnish, also, collections of every species 

 in greater numbers, larger size, and more rich in rare and precious 

 minerals and crystals, at any other prices that may be agreed on. 

 Accurate catalogues of our Magazine of Minerals of rocks and petri- 

 factions are distributed gratis. For accommodating the public, we 

 have made an arrangement, by which all the objects above mention- 

 ed may be obtained through any of the booksellers in Germany, who, 

 on their part, must draw their orders upon the bookstore of M. J. B. 

 Mohr, in this city. 



Le Comptoir de Mineraux a Heidelberg. 

 Heidelberg, Feb. 28, 1828. 



I will only add, that I have a few copies of the catalogues of min- 

 erals and petrifactions, (particularly of the latter) in this " Comptoir,''^ 

 and should be happy to loan them to any gentleman desirous of ex- 

 aming them. Respectfully, &;c. E. Hitchcock. 



Prof, of Chem. Min. kc. 



Amberst, Oct. 19th, 1829. 



8. Baron Humboldfs Expedition. — At a meeting of the Acade- 

 my of Sciences, on the 12th of October, M. Gay Lussac communi- 

 cated a letter, addressed to M. Arago by Baron Humboldt, dated 

 August 18, 1829. "This celebrated naturalist," says the Courier 

 des Electeurs, from which we translate the account, " having arrived 

 at the remotest frontiers of Siberia, has accomplished the objects of 

 his scientific voyage in a manner which has exceeded all his expec- 

 tations. He expresses the hope of returning to Berlin towards the 

 end of November. The Emperor of Russia has seconded this great 

 enterprize with a munificence truly royal. Not content with causing 

 the travellers to be accompanied with an armed force, he added to 

 them a raining engineer of distinguished merit. ' I cannot look upon 

 these tilings,' says the illustrious traveller, ' as tokens of personal 

 kindness and consideration. They are a public homage paid to the 



