The time for mining in dry diggings commences about the end of March and lasts till July, at which time water gets very scarce, and consequently digging becomes unprofitable, or even impossible. Some dig on the banks of rivers even in the spring when there is much water, but it is not a very profitable operation. The time when the rivers begin to fall by degrees is the month of June, and they continue falling till the next spring, when the melting snow again replenishes them; In August the snow from the mountains where they head, disappearing, they do not receive any new supplies, while the scorching sun keeps wasting them all the time, and in winter where it snows but does not rain they continue rather low; thus in winter time they are at their lowest ebb.--From the middle of September till the end of November is the best season for mining on the banks of rivers, as it is then that the lowest bars are uncovered, and even sometimes one may work in the very bed of the river itself. This is the time at which in many places, the current of a river may be turned aside with great facility. In so doing, miners should not rush blindly into the work without examining attending circumstances; dams have been made where there was not gold enough to pay one man’s day’s work. It is first necessary to see whether the hills in the neighborhood warrant the supposition that there must be gold in the river in that particular spot; then it is important to see where the current of the river would be most likely to make such a deposite; this being investigated properly, there will be a better chance for the company of miners to reap a plentiful harvest, should they determine upon the work. The months of July, August and part of September are sickly in the mines, and particularly on the Feather river and the Yuba. The sickness is owing to the extreme heat and carelessness on the part of the miners; some of them work in the hottest hours of the day, and sometimes not protecting sufficiently their head and body from the scorching rays. Fevers, diarrhœa and dysentery are the complaints commonly met with--occasionally scurvy shows itself; it is more apt to happen in winter time. But, however, whenever it occurs, it is owing entirely to the carelessness of the patient; a sufficient attention to the use of vegetable acids, as we have already mentioned, would prevent such occurrences.