Beginning the retreat

Thursday, September 25th, 1823 – I packed my gleanings of plants and seeds and specimens, and stood in readiness for the steamboat from Detroit, which came in the afternoon. In company with Mr Briscoe and family during the whole of the passage; we experienced a motion that could not be surpassed in an ocean. It blew a tempest the whole of the time. Towards Midnight on Sunday 28th we reached Buffalo, one of the wheels of the boat being swept away, and otherwise disabled.

Effectively, this marks the northern limit of Douglas's journeyings on this trip. He goes on to botanise around Niagara for a couple of days but in practice he has now given up on Canada and started to turn back towards New York. 

And what a journey back to Buffalo! He sets sail on, let's say, Thursday evening and reaches Buffalo just before midnight on Sunday. So he has spent three full days being tossed about in a tempest on Lake Erie, in a steamboat which is gravely disabled and must have been at some risk of foundering. I can't help thinking he has been lucky on this part of his journey and is perhaps secretly glad to be heading back to NYC.

The French Settlement, Upper Canada

Thursday, September 18th, 1823 – I set out in the morning in company with Dr Richardson for Sandwich, on the east bank of the River Detroit. For three miles up from Amherstburg the ground is thickly covered with woods. Passed a long settlement, intersected by natural ditches. On passing the swamp, which is fully four miles long, we came to what is called "The French Settlement" [in Upper Canada]. The fields are well cultivated and divided by fences; attached to each house is a neat garden laid out & kept with taste.

Upper Canada, the predecessor of modern Ontario, was created in 1791 by the division of the old colony of Quebec into Lower Canada in the east and Upper Canada in the west. A wilderness society settled largely by Loyalists and land-hungry farmers moving north from the United States, Upper Canada endured war with America, an armed rebellion, and half a century of economic and political growing pains until it was merged again with its French-speaking counterpart into the Province of Canada.

 The first leader of this new wilderness society was Lt-Gov John GravesSimcoe, whose avowed purpose was to create in Upper Canada a "superior, more happy, and more polished form of government," not merely to attract immigrants but to renew the empire and by example to win Americans back into the British camp. Governmental institutions were established, first at Newark (Niagara-on-the-Lake) and then at the new capital at York (Toronto). Simcoe used troops to build a series of primary roads, got the land boards and land distribution under way, established the judiciary, grandly abolished slavery and showed a keen interest in promoting Anglican affairs. When he left the province in 1796 he could take pride in his achievements — although he had failed to convert Americans from republicanism, and to persuade Britain to turn Upper Canada into a military centre. 

 During the war [of 1812] Upper Canada, whose inhabitants were predominantly American in origin, was invaded and partly occupied. American forces were repulsed by British regulars assisted by Canadian militia. The war strengthened the British link.

http://www.thecanadianencyclopedia.ca/en/article/upper-canada/

It's easy to see that Douglas is travelling in an uneasy and to some extent still-disputed borderland.  Tread carefully, Mr Douglas.

There are a few pears, which are scarcely seen in the western part of the State of New York; probably the emigrants took them from France at the first settling of the country. They have a few peaches, in appearance the same as in the States. I am informed they ripen in ordinary seasons; they have not that sickly appearance which they have in the States, occasined probably by excess of heat

Four miles from Sandwich the ground rises of a brown loam on gravel

Friday, September 19th, 1823 – [Douglas is botanising all day and his journal is essentially a catalogue of the plants he found.  Link is in the sidebar]