The greatest difference is observable between the waters of all these lakes, arising from soil, depth, and shores. Ontario is pure and blue, Erie pure and green, the southern part of Michigan nothing particular. The northern part of Michigan and all Huron are clear, transparent, and full of carbonic gas, so that its water sparkles. But the extraordinary transparency of the waters of all these lakes is very surprising. Those of Huron transmit the rays of light to a great depth, and consequently, having no preponderating solid matters in suspension, an equalization of heat occurs. Dr. Drake ascertained that, at the surface in summer, and at two hundred feet below it, the temperature of the water was 56 deg.. One of the most curious things on the shallow parts of Huron is to sail or row over the submarine or sublacune mountains, and to feel giddy from fancy, for it is like being in a balloon, so pure and tintless is the water. It is, like Dolland's best telescopes, achromatic. The lakes are subject in the latter portion of summer to a phenomenon, which long puzzled the settlers; their surface near the shores of bays and inlets are covered by a bright yellow dust, which passed until lately for sulphur, but is now known to be the farina of the pine forests. The atmosphere is so impregnated with it at these seasons, that water-barrels, and vessels holding water in the open air, are covered with a thick scum of bright yellow powder. A curious oily substance also pervades the waters in autumn, which agglutinates the sand blown over it by the winds, and floats it about in patches. I have never been able to discover the cause of this; perhaps, it is petroleum, or the sand is magnetic iron. Singular currents and differently coloured streams also appear, as on the ocean; but, as all the lakes have a fall, no weed gathers, except in the stagnant bays. The bottom of Ontario is unquestionably salt, and no wonder that it should be so, for all the Canadian lakes were once a sea, and the geological formation of the bed of Ontario is the saliferous rock. I have often enjoyed on Ontario's shores, where I have usually resided, the grand spectacle which takes place after intense frost. The early morning then exhibits columns of white vapour, like millions of Geysers spouting up to the sky, curling, twisting, shooting upwards, gracefully forming spirals and pyramids, amid the dark ground of the sombre heavens, and occasionally giving a peep of little lanes of the dark waters, all else being shrouded in dense mist.