At Atchinsk, which separates East from West Siberia, the travellers were received with graceful hospitality, but made no lengthened stay. Onward they sped, over the perpetual plains, intersected by forests of firs and countless water-courses. At Tomsk their reception was not less cordial than it had been at Irkutsk. Next they plunged into the immense marshes of Baraba; into a dreary succession of lakes, and pools, and swamps, blooming with a luxurious vegetation and a marvellous profusion of wild flowers, each more beautiful than the other, but swarming, unhappily, with a plague of insects eager to drink the blood of man or beast. Madame de Bourboulon had a cruel proof of their activity, though she had fortified her face with a mask of horsehair, and thrust her hands into the thickest gloves. "I was seated in a corner," she says, "wrapped up in my coverings; I lift the window-sash of one of the doors; the air is close and warm, the night dark; black clouds, charged with electricity, roll above me, and the wind brings to me the marsh-odours acrid and yet flat.... Gradually I fall asleep; I have kept on my mask, but the window-pane remains open.... A keen sensation of cold and of intolerable itchings in the hands and face awakens me; day has dawned, and the marshes lie before me in all their splendid colouring, but I have paid dearly for my imprudence; every part of my face which my mask touched in the position in which I fell asleep has been stung a thousand times through the meshes of hair by thousands of probosces and suckers athirst for my blood--forehead and chest and chin are grotesquely swollen. I do not know myself. My wrist, exposed between the glove and the edge of the sleeve, is ornamented with a regular swelling like a bracelet all round the arm; in a word, wherever the enemy has been able to penetrate, he has wrought indescribable ravage.... "At the next posting-house, I have the satisfaction of seeing that my travelling-companions have not escaped better than myself, and, thanks to the vinegar and water bandages we are forced to apply, we resemble, as we sit at the breakfast table, an ambulatory hospital!" The Baraba marshes measure 250 miles in breadth, and in length extend over eight degrees of latitude (from the 52nd to the 60th); a road has been carried across them, consisting of trunks of fir trees fastened together and covered with clay, but it is not very substantial.