342 Mr. Hatchett's Analysis 
In the mineral kingdom, a great variety of substances, and 
even some of the gems, exert a feeble degree of attraction on 
the magnetic needle, and sometimes also acquire a slight degree 
of polarity;* but, as this wonderful property has only been 
observed conspicuously powerful in one species of iron ore, this 
has been always emphatically called the Magnet ,-f and is said 
to consist of metallic iron combined with from 10 to 20 per 
cent, of oxygen. 
From the facts, however, which have been recently stated, we 
now find that there is another natural substance, apparently 
very different from the magnet in chemical composition, but 
nevertheless approaching very nearly to it in power, which is 
found in several parts of our globe, and particularly in a pro- 
vince of this kingdom, where it constitutes a vein, running 
north and south, of considerable extent, and several yards in 
width and thickness. 
From the experiments also, which have been made on the 
.artificial preparation of this substance, we find, that it is capable 
of receiving the magnetic properties when the proportion of 
sulphur amounts to 37 per cent, and is still powerfully attracted 
when a much larger quantity of sulphur is present. There 
is, however, some point at which all these effects cease, and 
this point appears to be, when the sulphur is in some proportion 
between 45 or 46 and 52 per cent. The preceding experiments 
have also proved, that iron when combined with phosphorus, 
likewise possesses the power of becoming a magnet to a very 
remarkable degree ; and, by the similarity, in this respect, of the 
• Cavallooii Magnetism, page 73. 
f In a future Paper, it is my intentiou to give an account of some comparative 
analyses of the varieties of this substance. 
