BLACK SANDS OF PARACALE. 931 
TABLE XIV.—Screen, amalgamation, and magnetic treatment test. Lot No.1. 
Assay of Weight 
Gold Gold Total | Assay of |nonmag-| Assay of ee Weight 
Screen. | Weight. icked amalga- | free gold| nonmag-| netic, | of mag- ars of mag- 
P * | mated. saved. netic. jincluding| netic. aS Se netic. 
free gold. . 
i Pesos Pesos Pesos 
Mesh. | Grams.| Moms. Moms. | Moms. | perton. | per ton. | per ton. | Grams. | Grams. 
10 487.0 90. 50 7.50 98. 00 96.30 410. 50 41.50 373.5 113.5 
20 657.5 157.00 4.90 161.90 264.60 | 1,773.60 12.00 129.5 528.0 
40 643.0 |_.-------- 60. 80 50. 80 207. 50 660. 10 4.00 185.5 507.5 
60 646.5 32. 50 32. 50 43. 80 197.20 3.20 256. 5 290.0 
80 784.5 20. 10 20. 10 72. 30 188. 46 3.20 367. 5 367.0 
100 569.0 12.85 12.85 18. 40 65. 70 3.20 295.0 274.0 
150 880.5 5.20 5.20 21.50 34. 70 4.50 466.5 414.0 
(—)150 ELD) ereeeescec| 15. 50 15.50 11.20 73.20 3.70 300. 4 260.5 
Column 3 shows the gold picked by hand from the 10- and 
20-mesh; this was added to the total gold saved as given in 
column 5. The large amount of free gold saved on each mesh is 
strikingly shown. This gold was added to the assay of the non- 
magnetic (of column 6) in order to obtain the total gold, either 
free or combined, in the nonmagnetic as shown in column 7. 
Tt is clearly seen that on every mesh the nonmagnetic product 
assays many times greater than the magnetic. The ratio of these 
assays with, and without, free gold is shown in Table XV. 
TABLE XV.—Showing ratios of assays of the nonmagnetic to the 
magnetic portion. 
« Ratio of total 
Haug Shee) assay of non- 
Screen. agnetic to | masnetic, plus 
1 ie ti free gold, to 
magnetic: magnetic. 
10 2.3 to 1 9.9 to 1 
20 22.0 to 1 148.0 to 1 
40 52.0 to 1 165.0 to 1 
60 13.7 to 1 61.5 to 1 
| 80 | 22.7 tol 43.4 to 1 
100 4.2 tol 22.8 to 1 
150 4.3 tol 7.0 tol 
(—) 150 3.5 to 1 22.8 to 1 
These ratios show the association of the gold with the non- 
magnetic on every mesh. As can be seen (column 3), on 40- 
mesh the maximum ratio of 165 to 1 and on the 150-mesh the 
minimum ratio of 7 to 1 are obtained. 
