FANNING AND EDDINGFIELD. P19 
from 190.06 pesos to 200.40 pesos. The results of the sampling 
- are more clearly shown in a table as follows: 
TABLE II.—Results of sampling. Lot. No. 1. 
Pestie@ all sae can ll Gree 
Pesos. Pesos. 
Sections cut from original_____---_____-_________________ 2 a es 86. 22 
i i il 235, 24 
Sections cut from original at 60-mesh___________________ : at a 31.44 
4 203. 80 
Section cut from original at 150-mesh___-______________- ; a 10.34 
| 
As shown by Table II, the 2 sections cut from the original show 
a difference of 86.22 pesos in value; sections cut after the ore 
has been put through 60-mesh show variations of 31.44 pesos, 
and sections cut after the ore has been put through 150-mesh 
show variations of 10.34 pesos. Fine grinding gives much closer 
checks, but the fact that considerable variations occur even in 
the 150-mesh product shows the exceedingly irregular distribu- 
tion of the values (due to the metallics) and the practical impos- 
sibility of obtaining absolute checks on lot 1 under ordinary 
conditions of sampling. 
Lot No. 2.—This represents the black sand concentrates from 
which the gold had been collected by passing it over the well of 
mercury and riffles as described on page 218. The gold content 
was considerably less than in lot 1, showing the advantage of 
using mercury in the cleanup; yet abundant free gold was pre- 
sent, indicating that even this method is inadequate. 
A quarter of lot 2 was cut out and pulverized through 60-mesh. 
This was divided into 4 parts, and each part was sampled and 
assayed separately. The following results were obtained: 
110.80 pesos, 109.56 pesos, 114.20 pesos, 114.40 pesos. These 
results are far more concordant than those obtained on lot 1, 
as is to be expected, since these are the amalgamation tails from 
the dredge cleanup from which a great deal of the free gold had 
been removed. Notwithstanding the use of mercury in the 
cleanup, some free gold still remained and was visible on the 
screens and was recovered in our amalgamation tests. 
Lot No. 3.—This represents a sample of the dredge tailings 
