374 Native Iron of Peru. 



plants Aeep may be fed and fupported, though they eat thofe plants only when they are m 

 wart of fuch as they arc accuftomed to. 



The manner in which I made the trials of plants upon (heep, were diftinguifhed as 

 follows: 



1. Thofe plants which they eat with a good appetite. 



■%. Thofe which they eat againft their inclination to appeafe their hunger. 



3. Thofe which they abfolutely refufed to eat. 



4. Thofe which caufed them to drink more than ordinary, which is a very bad fymptont 

 in Hieep. 



5. Thofe which produced much urine. 



6. Thofe which occafioned the colic in the ftomach. 



7. Thofe which purged. 



8. Thofe which caufed an evacuatioin of blood by the urinary paflage. 



9. Thofe which proved mortal. 



XIV. 



On the Native Iron of Peru, and en Mercury contained in Sea- Sab. 

 By Profeffor PsOV&Ty of Madrid* 



JL HE hiftory of the difeovery of native iron, by Don Rubin de Cells, is configned in the 

 Annales de Chiinie. Accident procured me fome frnall pieces, amounting to- about half an. 

 ounce in all, which I was curious in employing to refolve the problem of native iron. 



Before I expofed it to the agency of fol vents,. 1 examined its external cliaradters. The moft' 

 remarkable was, that it does not rufl as eafily as forged iron. My pieces, according to every 

 appearance, were taken from the external furfaee of the great mafe ; but at all* the places- 

 where the chiffel has paffed to cut them off, they preferve a whitenefs and clear-nefs which is- 

 afloniftiing, particularly when it is confidered that they have crofled the fea,, and have beens 

 kept feverat years in paper, which is the worfl covering we know of for rufting iron. 



Thefe pieces are very duitile, forge wonderfully well, are very foft under the file, andr. 

 •cannot be hardenedby ignition and cold water. When placed alongfidc of a piece of iron 

 filed and foftcjied to the fame degree, they are whiter, and.refemble fteel annealed and filed: 

 clean. 



I have diffblved one hundred grains in the aqueous fulphuric acid; and- they produced me 

 only 17a inches of hydrogen j whereas, at the fame temperature and preflare of. the atmo*- 

 ipherej foft iron conftantly afforded aoo inches. 



The folution was made with facility. Black particles are fcparated, but difappear towards 

 the end of the Ibludon,; fo that I could not decide that they were plumbago. 



•Joumal.de Ehyfique, VI.. 



