Year: 1875

We doubt if we could present more valuable local matter just at this time than the following taken from The Mining and Scientific Press of San Francisco:

 There is one very marked defect in our system of gold mining that does not exist in silver mining, and which the sooner remedied the better. We refer to an entire absence of all posi- tive knowledge as to what the ores be- ing worked contain. The skillful sill yer miner becomes daily, and often hourly, acquainted with the value of the ores being worked, and at the end of every run can figure up the percen- tage obtained and lost. If large loss he immediately begins to investi- gate the cause and seek remedy.

 This is not the case with gold min CTS, who are usnally perfectly oblivi- ous of what their ore contains, con- tenting themselves in cleaning up what they can and considering it the best they can do. In this they may be right and may not, as they have no reliable data to work from. Pos sibly were they to adopt the course pursued in silver mining, they would often be aroused to an effort for better ing their results, if they found a seri- ous loss was being sustained.

 It is asserted by MT Almarin B.. Paul, the inventor of the Paul process of dry amalgamation, that the gold mills of California do not on the aver age obtain ever one-third of the value of the ores. This conclusionis arrived at after ten years experience on ores from all sections of the State, and hundreds and hundreds of assays and other tests which he has made during this time. MT. Paul is not alone in this opinion, but other of our oldest and most practical men hold to the same belief.

 The opinion of many quartz miners is that they save from fifty to sixty per cent, but opinions as against posi- tive critical investigations are not to be received.

 Which view may be correct, we hope our gold miners will endeavor to determine by adopting such @ system of assays as is used in silver mining It is this close critical investigation into what they are doing, which not only makes silver mining popular but makes the silver miner the best possi- ble gold miner. His education is such that he investigates, and thinks it very singular that our gold miners know so little of the value of their ores except by comparison.

 Gold miners may say gold assays are unreliable. It Is not so much its assays as the manner of selecting the rock which is to be assayed. If it is desired to take the trouble to get at the value of the ores being worked, 1t can easily be done. But ores must not be selected from specimen pieces, or one piece made to answer for 8 whole batch. Several methods may be suggested. One is to have your feeder take piece of ore of given size from every shovelfull he fills for the battery, and after these pieces have accumulated to @ hundred pounds or more, have the entire lot pulverized, dry sampled and assayed. To be certain, have half dozen assays made and average the lot.

 Another and possibly easier but not so correct way, will be to collect every half hour a bucketfull of ma terial as it flows from the battery, be- ing careful to retain the water which often contains as much as the sands. Continue this during run, Allow the whole to settle we'll and then draw off the water carefully, dry the whole, mix we'll and properly sample for assay. This is but little trouble, and we think will tend to give our gold quartz miners some different views as to their loss and the value of their property.