"...the leaves,
as they are daily collected, being strung on threads and hung to
the roofs of the houses, which are without windows. When the
collection is finished the fumigation is begun by burning in the
houses the wood of "el Ez'r " ; the greener the wood the more
successful the fumigation. This gives the tobacco its black colour
and its almost aromatic odour. It continues till the following
April, but produces the best results in whiter, and especially
in February. When the tobacco is removed from the roofs it
is dry, and needs damping before packing."
19th century Syrian farmers may have simply hung up the green leaves high up in the smoke blackened rafters and ignored it all winter. The heating/ cooking being done with oak and other incidental materials fumigates the tobacco for the duration of the cool season. It is not out of the question- at least in my experience- that with a 15 or so foot high open beam ceiling and no chimney and no windows. The constant wintertime smoke density would be enough to create the Latakia curing.
In my way of thinking, rural 19th century Syria- open hearth/ no chimney cooking a heating is quite possible.
The thick, dense smoke just hangs there and find egress to the outside. But then again, Im a fan of 19th century English scientists. I find them to be highly rational and mostly objective observers.