France, 1810: Gehlen's opinion

1809: 1 Troy Ounce Platinum (Producer's Price)  = £ 0.80  (Fr 16.)
1810: 1 Troy Oz. Platinum (refined, wholesale)  = £ 0.60  (Fr 12.)

1810: 1 Troy Oz. Platinum (mfg, retail) = Fr 36.57 (£ 1.8285; USD$ 7.84)

1810: 1 Troy Oz. Platinum (Scrap, Bid) = Fr 15.24 (£ 0.762; USD$ 3.25)

1810: 1 Troy Oz. Platinum (ore, retail?) = Fr 12.19 (£ 0.6095; USD$ 2.60)

c.1811: 1 Troy Oz. Platinum (pure, retail) = Fr 30.48 (USD$ 6.53)

Janetty's Platinum was more than twice as expensive as Wollaston's and not better.  Gehlen refers to crucibles purchased five years earlier (c.1806) and there is no mention of price fluctuations for Platinumware throughout this period nor evidence elsewhere.  Though notably different, Wollaston's and Jannetty's prices presumably remained consistent or range-bound for 1805-10, or the involved discussion makes little sense.  

 In 1810, the labor and profit for Paris Platinum was over Fr. 21 per Troy Ounce, an extraordinary markup that soon collapsed with Cuoq's massive importation in 1812.  

Ambiguously, the cited Paris High Price for platina/ore might refer to either a local shortage or the general commodity spike during the Continental Blocus (circa 1806/7); Wollaston never paid nearly so much for platina.  This seems to confirm a general French dependence of British merchants for the Colombian ore, but also suggests the Paris Price Collapse in 1812/3 was driven by reason altogether.  

Donald McDonald (1960) erroneously transcribes the Number 3>5 (a common typographic confusion with 19th C. documents)  quoting Gehlen : "Janety 'charges 56 francs per ounce and only pays 15 francs for old platinum' (33). He goes on to remark 'the difference is a little steep! Raw platinum can be bought in Paris for at most 12 francs per ounce' in 1812."

This peculiar printing and confusion of the numeral (3>5) occurs as late as the 1850s in some primary sources.  There's also no record of the refined price rising 20% ('36 Francs per Ounce') before a well-known Paris Price Collapse in 1813.  The unmanufactured refined Pt price was Fr 31./Troy Ounce in late 1810 or early 1811.


Citation: Journal de physique, de chemie, d'histoire naturelle et des arts, Vol. 75; François Rozier (1812) p.186

Allgemeine Handlungs-Zeitung: mit den neuesten Erfindungen und ..., Vol. 20 (1813) p.675
Citation: Jahrbuch der Chemie und Physik, Vol. 7 (1813) p.309

AF Gehlen:
" The chemist may be connected to Mr. Leithner consider more so than some now, and that at moderately price, a pot, etc. of platinum will be able to provide, where the opportunity is not as open to like, to let it come to much dear prices of Janety in Paris. In addition, I must note after several experiences, that Mr.Janety seems not to be very far advanced in the art of working the platinum , or at least, that the success of the exercise is not always the same. I found here in the physical cabinet in front of a platinum crucible, which has held for five years, virtually indestructible, even though he was constantly and heavily used, and not once has a bent rim. Others I received from him since then, have been nowhere near as good, and one of them, which was manufactured against the appointment without bending of the rim, got a few months to several places of the edge cracks, which are at least 0.5 inches hineinerstreckten. That Janety's not quite pure platinum Sey, is evident from its spec. Weight. I have a piece to a square Zain forged from pure platinum Wollaston near 2:25 oz weight. This showed me a spec. Weight of 21:04, a parallelepiped piece Janety'schen platinum, however, of more than four ounces of the hold only 20.01.
...
An even greater difference than in the purity is between price of platinum from Wollaston and Janetty.  From the former, it costs twelve shillings the ounce, the latter extracts 36 francs an ounce and credits scrap platinum only 15 francs.   The difference is a bit steep.  You could get crude platina in Paris up to 12 francs the ounce.  You thereby have enough to fix it yourself and yet still have extra metal. That mentioned above Janety's platinum I would not have if it had not been a most disgusting improvement of the given order that purified platinum purchased instead of raw platina."

Mr. Guyton Mouveau of the Institute. -1810. - The Platinum of Santo Domingo was identified in the sands of the River Jaki, in the foothills of Sibao in the eastern part of Santo Domingo, it is there found in small flattened grains, as observed in the gold sands of Choco, Santa Fe, The Peru, but they are usually a little bigger.  These sands also contain some gold.  We owe this knowledge to Mr. du Bizy, Surgeon-Major.  Some hectogrammes of ore, after having undergone a mild calcination, were washed under sulfuric aci, by Mr. Jannety, and they revealed a few flakes of gold.  Société Philomathique, 1810, page 77.  Annales de chimie, same year, Volume 73, page 334. 




February 10, 1810:

M. Janety has presented to you:
( 1 ) Ten platinum medals of the same diameter but of different types.
(2) A bucket shaped vessel 189 millimetres in diameter and 135 millimetres deep
that has been flattened and hammered until it weighs only 160 grammes.
(3) A retort with neck capable of holding 1 litre and weighing only 800 grammes.




February 1810: Platinum was predicted to become 25% the Price Of Gold in a few years.

 The Platinum just found in Spain and Santo Domingo is becoming more common every day in trade and which must necessarily diminish value; we can, from this, think {Platinum} in the next few years will be in ratio less than  1 to 4 the price of gold.






Aaron Burr, resident in Paris, went to Janetty's for Platinum for a dental operation with Dr. Nicholas Fonzi.  Patients purchased their own Platinum and deposited 'in kind' with the illustrious dentist.  In all likelihood, the same amount of Platinum wire required for each tooth.


 
December, 1810:

Citation: The private journal of Aaron Burr, during his residence of four years in Europe,  Vol. 2;  Aaron Burr, Matthew L. Davis




London, 1812: Burr apparently bought Platinum at the shop of Percival Johnson (Maiden Lane, Wood-Street) for repairs to Fonzi's Platinum denture.