Springs at Lemington Priors. 207 
XVI, THE SPONTANEOUS PRECIPITATE. 
This water is pellucid when it first rises from the 
spring; in small quantities it does not lose its tran- 
sparency; a very small sediment is deposited by 
boiling, so small indeed that sufficient cannot be 
collected in this way for examination. However, 
when the bath has been newly filled, in some hours 
the transparency of this large body of water is de- 
stroyed by exposure to the atmosphere, and it con- 
tracts a whitish colour. I collected a large quantity 
of this precipitate from the bottom of the bath; 
where it by degrees accumulates, having been depo- 
sited from a large body of water, which is very fre- 
quently renewed. 1. I first attempted the analysis of 
this powder by acids, but was disappointed. It is 
hardly soluble in any of the mineral acids: they all 
take up a little of it, make a brisk effervescence, and 
excite heat when first applied; but neither by a long 
digestion, nor by boiling, could I saturate the acids ; 
nor, by putting a very small quantity of the powder 
into a large quantity of acid, could I completely dis- 
solve the powder. 
2. But, by the use of the blowpipe, it readily ap- 
peared, that this sediment is no other than the oxyds 
of the two metals so frequently mentioned, iron 
and manganese. It may be made magnetic; it gives 
the hyacinthine colour to borax, the colour is de- 
stroyed by continuing the fusion, and may be re- 
