Adam Smith may have had an opportunity to visit David Hume’s old stomping grounds, the luxurious Hôtel de Brancas on the rue de l’Université, on Sunday, March 16, for Horace Walpole’s journal entry for that day reads: “To Hôtel de Brancas, Duke of Buccleuch etc. there.” Does the “etc.” in this entry include Adam Smith, who was Duke Henry’s tutor and chaperone at this time?
At the time, the Hôtel de Brancas (pictured below) was the British ambassador’s luxurious residence in Paris. It was located on the rue de l’Université, less than two kilometers from the Hôtel du Parc Royal where Adam Smith was lodging at the time, and it was built in an Italian style. Its tranquil gardens extended all the way up to the banks of the Seine, and even today, the gardens of this mansion extend a few hundred yards up to the Quai d’Orsay, a busy thoroughfare on the left bank of the Seine, opposite the Place de la Concorde. (As an aside, Louis-Joseph de Bourbon, the 8th Prince of Condé, acquired the Hôtel de Brancas in 1868, but it was later confiscated by the government during the Revolution. Today, the Hôtel de Brancas is the official residence of the President of the National Assembly (France’s legislature) and is located on 128 rue de l’Université.)
Smith would have a good reason to visit the Hôtel de Brancas, for this building was not only the official residence of the British ambassador to France, the epi-center of the English-speaking world in Paris; it was also the former residence of Smith’s intellectual mentor and closest friend, David Hume, who had an apartment and worked at Hôtel de Brancas from March 1764 to November 1765, when Hume was Secretary to Lord Hertford, the British ambassador. (Hume became Charge d’Affaires of the embassy, the de facto ambassador, when his superior, Lord Hertford, who was then the official ambassador, left Paris in August of 1765 to attend to some private matters. Hume was Charge d’Affaires until a new ambassador, the Duke of Richmond, arrived to replace Lord Hertford in November of 1765. It was at that time that Hume moved to the Hôtel du Parc Royal.) Ernest Mossner (1980, p. 490) describes Hume’s apartment at the Hôtel de Brancas thus:
During the first of several months in Paris, Lord Hertford had resided at the Hôtel de Grimberg in the rue St Dominique, but in March 1764, he took the Hôtel de Brancas … at the junction of the rue de l’Université and the rue de Bourbon. This large mansion near the Louvre–“quite a palace” remarked Lady Sarah Bunbury–cost him L500 annually. He had some thoughts of relinquishing after a year but retained throughout his embassy. In it there was a separate apartment for David Hume, certainly the most luxurious that man of letters had ever had.”
As an aside, it’s a shame that Hume and Smith did not get to see each other in Paris in 1766, for Hume departed the City of Lights on January 4, 1766, while Smith did not arrive until February 15. Imagine what their private conversations in the gardens of the Hôtel de Brancas would have been like. (This counterfactual is perhaps the greatest of the unintended consequences of the Rousseau affair, of which I shall have more to say later in this series of blog posts.)
In any case, we don’t know if Adam Smith accompanied Walpole and Duke Henry to the ambassador’s residence on this particular day (Sunday, March 16), or if he had an opportunity to visit Hume’s old apartment there, but he must have visited this place at some point during his residency in Paris. The British ambassador not only resided and conducted his official business here; he also hosted many dinners and receptions at his residence during his tenure as ambassador, and Walpole visited here many times during his sojourn in Paris.
In Chapter 1 of Book 5 of The Wealth of Nations, in the subsection titled “Of the Public Works and Institutions which are necessary for facilitating particular Branches of Commerce,” Smith describes the history of embassies and explains why ambassadors are necessary public expenses:
“Among other nations, whose vigorous government will suffer no strangers to possess any fortified place within their territory, it may be necessary to maintain some ambassador, minister, or counsel, who may both decide, according to their own customs, the differences arising among his own countrymen, and, in their disputes with the natives, may, by means of his public character, interfere with more authority, and afford them a more powerful protection, than they could expect from any private man. The interests of commerce have frequently made it necessary to maintain ministers in foreign countries where the purposes, either of war or alliance, would not have required any. The commerce of the Turkey Company first occasioned the establishment of an ordinary ambassador at Constantinople. The first English embassies to Russia arose altogether from commercial interests. The constant interference which those interests necessarily occasioned between the subjects of the different states of Europe, has probably introduced the custom of keeping, in all neighbouring countries, ambassadors or ministers constantly resident even in the time of peace. This custom, unknown to ancient times, seems not to be older than the end of the fifteenth or beginning of the sixteenth century; that is, than the time when commerce first began to extend itself to the greater part of the nations of Europe, and when they first began to attend to its interests.”
In other words, embassies in foreign nations are a necessary public expense because they help promote commerce and trade among nations. But what happens when a government enacts measures that restrict trade and commerce? This was not just a theoretical question; as I shall explain in my next post, it was a real-time issue that Smith himself would confront during his stay in Paris.
 Lewis 1939, p. 308.
 This central street had existed since 1368 but was originally called Pré-aux-Clercs; it was renamed rue de l’Université in 1640. See Hillairet 1964 (Vol. 2), p. 582.
 The upper floor of this mansion was added later. Baggini 2021, p. 129.
 See Gallet 1995, p 61.
 See Baggini 2021, p. 128. See also Hillairet 1964 (Vol. 2), p. 588.
 This particular mansion is not to be confused with a private town-house of the same name, l’hôtel de Brancas, located on 6 rue de Tournon. The town-house that Walpole is writing about was originally built for the Marquis de Lassay from 1726 to 1730 and was thus originally known as “l’hôtel de Lassay.” See Baggini 2021, p. 129; see also Hillairet 1964, p. 588. After Lassay’s death in 1750, the ownership of the town-house was transferred to the Brancas family. Baggini 2021, p. 129
 Lord Hertford had appointed Hume as his Secretary back in 1763 when Hertford was named ambassador to France, but Hume did not officially receive his commission as Secretary of the Embassy until July 13, 1765. That same month, Lord Hertford was appointed Lord-Lieutenant of Ireland.
 Mossner 1980, p. 490.
 The Wealth of Nations, Glasgow edition, p. 732 (paragraph 2).
 Today, however, embassies also conduct many espionage activities and are often accused of meddling in the domestic affairs of their host nations. This expansion in the role of embassies poses a delicate questions for students of political economy today: should embassies be limited to their original function of promoting commerce and free trade?