116 ILLUSTRATIONS OF THE BOTANY OF [ Thea. 
if we compare the range of the thermometer in the two latter periods, or during the 
month of November, when the embassy passed from 31° to 28° 40° of N. latitude, as 
before, with some place in India, we shall find that Saharunpore, in lat. 30°, and 
elevated 1,000 feet, approximates in climate during this month, as the thermometer 
ranges from 45° to 55° in the mornings, and from 60° to 84° at the hottest time of the 
day, which is always, at least, two hours after noon. If we suppose the decrease of 
temperature to be only equal to what takes place at Saharunpore, we shall have a 
mean temperature of 52° in the coldest month, January; with the thermometer some- 
times down to the freezing point, and ranging up to 65° in the warmest part of the 
day: but the extremes we know must be greater from what takes place both at Canton 
and Pekin, on account of the eastern exposure of China. This is confirmed by Mr. 
Reeves, who informs me, that ‘‘ snow has been on the ground for days together upon 
the green teas, and the manufacturers of the black tea complain of the coldness of 
their country at times.” With respect to moisture, we have seen that the largest pro- 
portion of rain falls at and near Canton, while the sun is in the neighbourhood of the 
tropic of Cancer; so that there may be said to be a rainy season there, though not so 
decidedly as in Bengal; and Mr. Reeves has known the black-tea manufacturers com- 
plain ‘‘ that their first picking (in May and J une), often suffers from rain, and cold 
easterly winds.”’ 3 
These few indications of the climate being premised, it would be interesting to con- 
nect with them a precise idea of the vegetation; but this is hardly attainable, as so little 
is known of the interior of China, from the want of competent observers of the localities 
of plants; but there is. no doubt that the vegetation must differ in the northern and 
southern provinces, and also, where these consist of elevated lands or of plain country. 
From Du, Halde, and the progress of the British embassies through the provinces of 
Pe-che-lee, Shan-tung, and, the northern portion of Kiang-nan, we learn that from 
Tien-sing nearly to, Nankin, or from N. lat. 39° to about N. lat. 32°, and in a S.E. 
direction to the termination of the grand canal at Hang-cheu-foo, the country consists 
of level and extensive alluvial plains, rich and highly cultivated; intersected by numérous 
rivers and canals, and:covered in some places with extensive swamps and broad lakes. 
In the most northern parts of this. tract, with many genera found in temperate and 
European climates, we find some plants, which we should expect to find only in more 
southern latitudes, as Lagerstremia. indica, Ipomea Quamoclit, Celosia cristata, Gom- 
phrena globosa, species of Gynandropsis, Tribulus, Clerodendron, &e.; the lakes abounding 
with Nelumbium speciosum, Trapa. bicornis, Pontederia vaginata, and others; while the 
fields are cultivated with rice, millet, cotton, sesasum, and. castor-oil plant. Sida 
tiliefolia, referred by Dr. Roxburgh to S. abutilon, affords fibres for rope-making ; and 
the gardens capsicums, gourds, melons, and water-melons, the egg-plant, yams, and 
sweet potatoes, with species of Saja, Dolichos, and Lablab, all of which are also culti- 
vated in every part of the plains of India. 
As the two embassies separated at the great river Yang-tse-kiang, and both shortly 
afterwards 
