70 On the Orbit. of the new Planet, 



more than sufficient to solve the question I proposed ; th,cy 

 indeed establish, in an inconttstable manner, that pure 

 nickel really possesses the magnetic virtue which ^t'rgman 

 and several chemists with him did not hesitate to ascribe to 

 it: thev prove that this property, which it participates with 

 iron, and no doubt with cobalt, may be masked or destroyed 

 in these metals by their union with different bodies, and par- 

 ticularly by arsenic. Hence we necessa.rily deduce this con- 

 sequence, that a magnetic bar is an incorrect in.Hrument for 

 detecting" then:, and cannot v/ith certainty indicate the pre- 

 sence of them; hut wltere they are in a state of mixture 

 only, and not in that of combination, they "confirn^ the pro- 

 perty of semi-ductility, which has been some lime observed 

 in it, and its relation n\ thi^ point of view to zii^c and mer- 

 cury. They show that it i? much more difficult to fuse it than 

 has been hitherto supposed, and give reason to presume 

 that it has never vet been obtained but allayed either with 

 arsenic or cobalt. They show tha! it is susceptible of hypcr- 

 oxvc^-'nation, and of forming a nev.- black oxide, soluble in sul- 

 phuric andnitricacid, with a disengagement of oxygen, and in 

 muriatic acid with a disengagement of oxygenated muriatic 

 acid. Theyconfirm the p;\SL•nccQfbi^■n^uth in ore of nickel, 

 and the transition of the latter to the state of ineoluble arse- 

 iiiate when treated by nitric acid. They give a sure method for 

 extracting arsenic from any ore whatever, and of determin- 

 ing the quantity. In the last place, they furnish a process 

 free f^mi every susj-Mcion, which was vvanting to analysis, 

 and which was long desired, for separating nickel from co- 

 balt and iron, and consequently fc<r obtaining the first two 

 metals in their greatest state of purity. 



VIII. On the Orbit of the new Planet discovered In/ JMr. 

 ■ Harding at the Obseri'atnnj if l^ilienihal, nea,r Bremen ^ 

 en the 1st of' Svpieyiber 1 804. 



JLJ-AviNG been favoured by an eminerit asitronomcr with a 

 chart (see Plate III.) representing the apparent path of the 

 new planet, accompanied with the following observations 

 in regard to the use of it, we flatter ourselves it will prove 

 gratifying to our astronomical readers. 



" The j^pparent path of the new planet was laid down in 

 this chart fn^m observations macle froni September i'9 to 

 October 12, 1804. The remaining part of theorbit, which 

 is carried on to the middle of November, was hid down on 

 ft supposition tliat tlie planet's mean distance is about the 

 saqic as thi^t of I'alUs^ as the retrograde uiotion seems nearly 



tu 



