REMOVAL OF SILVER AND GOLD BY MUNTZ METAL. 351 
crucible, and maintained at that temperature for fifteen or twenty 
minutes; the heat was then gradually raised till the mixture 
fused, and afterwards increased to whiteness; as soon as that 
temperature was attained, the crucible was withdrawn from the 
fire. Thirteen operations of this kind yielded 124 grams. of lead, 
and the silver contained in this was found by cupellation (deduct- 
ing that which was yielded by the lead alone, in a test experiment) 
to amount to 0:0005 grm. Now, as this demi-milligramme of 
silver was extracted from fifty litres of sea-water, it follows that 
one hundred litres—or for simplicity, say one hundred kilo- 
grammes of sea-water—contain one milligramme; hence the pro- 
portion of salt in sea-water is, approximately, one part in 
100,000,000, so that a cubic myriametre of sea-water contains 
1,000 kilogrammes, or a cubic mile (English) contains about 23ibs.! 
avoirdupois. This estimation must be regarded as a minimum ; 
for all the preceding operations are attended with slight loss.” 
- In the same paper, they refer to the presence of silver in certain 
fuci, amounting to yov'svo; in various trees such as oak, birch, 
beech and apple, also in the blood of an ox and the vegetables 
upon which it had been fed. They also found it in rock salt and 
in coal, but as the coal contained pyrites, they do not attach the 
Same importance to its presence in this case. 
“On the existence of silver in sea-water, by Frederick Field, F.C.8.” 
He examined the sheathings of certain traders as follows :— 
“Ana Guimaraens,” a Chilian vessel, trading up and down the 
South Pacific for seven years. Yellow metal from the bottom of 
Vessel ; 5,000 grains were dissolved in pure nitric acid and the 
‘olution diluted ; a few drops of hydrochloric acid were added 
and the precipitate allowed to stand for three days. A large 
ee ee 
“ada sea-water represents over 40 tons of silver per cubic mile, not 
“ara » 48 given in the above translation. Malaguti is not respons! 
r, as it does not occur in the original, where however, there 
kilos op Crent CIFOR: since “0005 g. for 50 litres is said to be equal to 1000 
. of silver per cubic myriametre instead of to 10,000,000 kilos. 
Proe. Royal Society London, Vol. vitt., 1856-7, p- 292. 
