As a matter of curiosity, however, connected with this subject, it is interesting to know what is the experience of other gold regions in these particulars. In Bohemia, on the lower part of the river Iser, there were formerly gold-washings. “The sand does not now yield more than _one grain of gold in a hundredweight_; and it is supposed that so much is not regularly to be obtained. There are at present no people searching for gold, and there have been none for several centuries.”[13] This, therefore, may be considered less than the minimum proportion which will enable washers to live even in that cheap country. In the famed gold country of Minas Geraes, in Brazil, where gangs of slaves are employed in washing, the net annual amount of gold extracted seems to be little more than £4 a-head; and in Columbia, where provisions are dearer, “a mine, which employs sixty slaves, and produces 20 lb. of gold of 18 carats annually, is considered a good estate.”[14] These also approach so near to the unprofitable point, that gold-washing, where possible, has long been gradually giving way, in that country, to the cultivation of sugar and other agricultural productions. In regard to Siberia, Rose, in his account of his visit to the mines of the Ural and the Altai, gives the results of numerous determinations of the proportion of gold in the sands which are considered worth washing at the various places he visited. Thus on the Altai, at Katharinenburg, near Beresowsk, and at Neiwinskoi, near Neujansk, and at Wiluyskoi, near Nischni Tagilsk, the proportions of gold in 100 poods[15] of sand, were respectively— Katharinenburg, 1.1 to 2.5, or an average of 1.3 solotniks. Neiwinskoi, ½ solotnik. Wiluyskoi, 1½ solotnik. These are respectively 72, 26, and 80 troy grains to the ton of sand; and although the proportion of 26 grains to the ton is little more than is found unworth the extraction from the sands of the Iser, and implies that nearly 19 tons of sand must be washed to obtain one troy ounce of gold, yet it is found that this washing can in Siberia be carried on with a profit. In the gold-washings of the Eastern slopes of the Ural, near Miask, the average of fourteen mines in 1829 was about 1⅛ solotniks to the 100 poods, or 60 grains to the ton of sand. The productive layers varied in thickness, from 2 to 10 feet, and were covered by an equally variable thickness of sand and gravel, which was too poor in gold to pay for washing.[16]