Balata and the Balata Industry. 201 
whether the milk will run well or not. A nick is made in 
the bark with the cutlass, and the milk is watched closely 
for a moment as it issues from the wound. The col- 
lector is never deceived in this test, and he does not 
hesitate, if he is not satisfied, but moves immediately to 
another tree. By this test, too, they can judge with a 
very close approximation what quantity a tree will give. 
They count in bottles, six of which go to the gallon, and 
they are rarely a bottle out in the estimated yield made 
before the tree is felled. Considerable influence is as- 
cribed on the yield of milk to the lunar seasons. This is 
a very common popular theory in regard to the amount 
of sap in trees held by woodcutters as affecting the qua- 
lity and character of wood in various ways, but it requires 
to be established by scientific observation. During the 
flowering season of the trees, too, colle6tors say the yield 
of milk falls off largely, to as much as half in some cases. 
This and their other statement that when a tree is felled 
and allowed to lie upon the ground for a day the whole 
of the milk ascends to the foliage require the attention 
of scientific investigators also. They would seem to 
indicate that the milk, under the conditions mentioned, 
was taxed in the elaboration of tissue, and though I think 
myself that under certain changes it is absorbed, I am 
disposed to believe that in these cases the demand on the 
sap leaves the balata in a more or less concrete state in 
the cells, devoid of the degree of fluidity necessary for 
it to run from the bark. That it remains in the bark is 
shown by Mr. FRANCIS'S investigation quoted further on. 
When a tree is felled the expiration of moisture from 
the foliage, which continues as before till it is quite 
exhausted, alone must produce this state. These are im- 
BB 
