^Msmo'ir on Nickel. 69 



it has been obtained always allayed, either with arsenic, or 

 sometimes, no doubt, with cobalt. 



Though I had lost a great deal of nickel In these different 

 attempts to fuse it, I however extracted a quantity more 

 than sufficient to establish (hat property of it respecting 

 which there appeared to be any doubt. 1 here allude to its 

 magnetism. I can assert, therefore, tliat the magnetic 

 virtue in it is so striking, that it is almost equal to that of 

 iron; and vet it is certain thaiit contains none of that metal ; 

 for, if it were indebted for it to iron, it is so strong that it 

 oaght to contain at least one half of its weight of that 

 metal : in this case chemistrv would furnish a variety of 

 means for delecting it; but by all those which it possesses, it 

 cannot discover in nickel the least trace of that metal; and 

 if only l-50th or even l-lOOth part of that metal be added, 

 it immediately becomes sensible by re-agents. It appears, 

 thertfbre, to be mathematically demonstrated, if I may use 

 the expression, that nickel is really susceptible ol attraciion ; 

 and those who still doubt this truth ought, in admitting 

 these experiments, to be perfectly convinced of it. Several 

 chemists, indeed, have obtained someof it which had no ac- 

 tion on the magnetic needle : but it was not pure ; they had 

 not separated it from all those matters which alter it ; in 

 particular, they had not separated it from the arsenic which 

 mav mask its masinetism ; as is proved bv the experiments I 

 liad made on that subject, and witli which I shall terminate 

 this memoir. M. Chenevix has himself acknowledged, that 

 the nickel not susceptible of attraction, which he obtained, 

 had ill it a mixture of arsenic. This error could not long 

 tscape so distinguished a chemist. 



Having fused together equal parts of nickel atjd arsenic, 

 I obtained a brittle allay, granulated, easy to be fused, and 

 which wa^ not susceptible of attraction ; half a part of ar- 

 senic is sufficient to mask the property of iron ; a quarter 

 only weakens it. I made the first of these allays by heating 

 in a crucible equal parts of iron and arsenic, and the second 

 with one part of iron and half a part of arsenic. I was 

 desirous to ascertain whether other metals, and partieularly 

 copper, would also have the property of rendering iron un- 

 susceptible of attraction. 1 made four of these allays: in 

 tlie (nsl I put a fourth of iron, in the second an eighth, in 

 the third atuelfth, and in the fourth a sixteenth: alloflheni 

 vcre magnetic, and were the more so, as they contained 

 more iron, and the more ductile, as they contained less. Bv 

 dissolvinn; them in acids the presence of iron was easily 

 d»-tected by gall-nuts. Such is the series of experiments of 

 wlucti this memoir is composed : if not numerous, they arc 

 E 3 more 



