According to Consul-General Guenther, of Frankfort, German papers state that it happens frequently that the roots of fruit trees are more exhausted than the parts above the ground, and so the life of the tree is threatened.
In order to prolong its life in such cases, it has been recommended to vaccinate the trunk of the tree with a solution of sulphite of iron, the same article which is used in the so called anaemia or chlorosis (Bleichsnckt) of the grapevine. A Russian scientist, Mr. Sigismund Monrjetski, has now made minute scientific experiments with reference to the results of such vaccinations, and by employing colored solutions he has shown that the solution never enters into the old wood. It only follows the young growth, but it penetrates into the roots down to a depth of 1 meter (about 39 inches), while on the other hand, it penetrates up to the top of the tree. It is therefore deemed best to vaccinate the tree through a single opening of the neck of the root, and it should serve not only for the introduction of nutritive substances, but also of such liquids which, by killing certain bacteria, tend to cure diseases of the plant.