UK, 1800: Cost of Platina, Platinum

In late 1798, the sudden appearance in London of "a number of bars of platina" suggests a sudden market glut and Platinum price decrease in London, 1799; also, a previously higher price.   Where these bars came from is unspecified - the 4,000 ounces seized in late 1797 ?

Does that notable event help explain why Wollaston's 1805 manufactured price was 75% lower than the import manufactured price cited by Knight in 1800?  (Paris-refined prices may have persisted at higher rates, despite cheaper ore and absent any other 'global' producer competition.)  The wholesale Platinum price was certainly falling, 1798-1805: bars of malleable Platinum came from Paris, presumably.

On 24 December 1800, William Hyde Wollaston and Smithson Tennant entered into financial partnership with a major purchase of 5,959 English Troy Ounces (408.6 English Pounds avoirdupois; 405.28 Spanish libra) of alluvial platina ore at an estimated at 76.27% purity for £795.   See Cambridge University Library Add. MSS 7736, notebook LI. 

It is generally assumed Wollaston's first major platina purchase had been smuggled from Nueva Granada (now, Colombia) to Kingston JAMAICA and thence to London at a wholesale bulk market-price.  But in fact large amounts of seized and auctioned platina, captured from Spanish treasure-ships by British privateers or H.M. vessels almost certainly reached the English market at greatly reduced prices, 1799-1805.  

Wollaston & Tennant's business began merchandising malleable Platinum in 1805. Refined retail Platinum prices in the UK were very stable from 1805-1820, despite fluctuating ore rates.

Wollaston's cost for alluvial ore varied somewhat, and the initial outlay for ore was a relatively low price for his platina purchases, 1800 -1817.  From his Notebooks (recording expenses, commissions, division of profits, income, division of profits, etc.) a great deal may be surmised about the pricing of malleable Platinum:

c.1798: 1 Troy Ounce Platinum (imported French manufacture)  ~ £ 4.26 (USD$ 18.69)

1799-1800: 1 Ozt. Platinum (French ingot, retail) ~ £ 1.864

 

1800: 1 Ozt. platina (Wollaston's initial cost)  = £ 0.1334 (USD$ 0.5853)
1800: 1 Ozt. platina (at purity)  = £ 0.1749 (USD$ 0.7675)

1805-15: 1 Ozt. platina (producer cost)  = £ 0.16 -  0.27 (USD$ 0.63 - 1.25)

1805-15: 1 Ozt. Platinum (refined, whols.)  ~ £ 0.34 (USD$ 1.24 - 1.68)

1805: 1 Ozt. Platinum (refined, retail)  = £ 0.75 - 0.90 (USD$ 3.26 - 3.92)

Citation: Elements of chemistry: comprehending all the most important facts and ... Robert Heron, Antoine-François de Fourcroy (comte), Jean-Antoine-Claude Chaptal (comte de Chanteloup) 1800 p.353

c.1815 history of platina:

Citation: The National register, Vol. 1, Dated 8/3/1816 p.365

1800:  £ 1. = Fr. 24.5238 = S$ 5.0762; 
1800:  S$ 1. = £ 0.1970 = Fr. 4.8311
1800:  Fr. 1= S$ 0.207 = £ 0.0408