Alkalis In Colorado 
15 
chlorid had done no harm whatever. I only wish to state that the 
trees in these spots where there was enough of it present to keep the 
surface so moist that it was actually darker in color than the rest of 
the surface, were neither better nor worse than the rest of the orchard. 
HOW SALTS AFFECT PLANTS 
I have tried to make the preceding statements clear, but there 
are some things that badly need explanation and even then will remain 
unsatisfactory. A solution may enter the plant and travel through 
every part of it and kill it. Just how this is done is for the plant 
physiologist to tell us but we know that, if we allow a solution of sodic 
arsenite to come in contact with the feeding roots of one side of an 
apple tree for instance, this sodic arsenite travels very quickly even to 
the ends of the branches, and wherever it goes, it kills. We can follow 
this sodic arsenite up the roots, through the trunk of the three and into 
the individual branches, and we find dead tissues wherever it goes 
and live tissue wherever it did not go. We can also recover arsenic from 
this dead tissue. The solution need not be very strong. It enters the 
tree with the water that the roots take up. A similar solution of sodic 
chlorid (kitchen salt) would have been taken up too, perhaps. A 
very much stronger solution was taken up in a case in which I put 
25 pounds of salt about a four-year-old tree, but it did not kill the 
tree. The sodic arsenite is a poison and it kills every living cell that 
it meets in its course up the roots, trunk and limbs of the tree. This 
is one way in which a poison may act. 
Destroy Root Hairs 
We are thinking of a poison as anything that will kill the plant. 
If we could take all of the little hairs off of the roots of a tree so that 
it could not get water to kee/p it fresh and moist it would dry up and 
die. We can cause it to do this by bringing strong solutions of certain 
salts into contact with these little hairs, when they will refuse to take 
up any water. The result is that the sun, the wind and the dry air 
take the moisture out of the leaves and none can take its place because 
these hairs on the roots which have been supplying the water to the 
leaves and limbs have stopped functioning, the leaves burn, and the 
plants may even die. Salts which will not ordinarily kill the plants, 
like the sodic arsenite, may be made into solutions strong enough to 
kill in this way and then you may not find them in the leaves or in the 
trunks for the root hairs refused to take them up. I do not know 
how strong a solution of any salt may have to be before it will do this, 
but I believe that nitrates do act in this way, in many instances, and I 
think that ordinary alkali salts, may act in this way too. In this case 
it amounts to killing the root hairs which is worse for the tree than 
