2 
CAROLINE RUMBOLD 
Hum. In 1887, Gaunersdorfer (4) published the results of seven years of 
experimentation on the effect of lithium sulphate on plants. He injected 
small conifers without injuring them and found that the plants finally- 
eliminated the salt introduced into them through the roots by throwing it 
off with the leaves and bark. He believed young shoots, leaves, and re- 
productive organs were protected from the lithium by the lack of lignified 
water-transferring tissue. Physiologists such as Sachs (5), Strasburger 
(6), Wieler (7), and Pfeffer (8) established the fact that some substances 
foreign to plant tissues could be safely conducted through them. At the 
same time a large number of substances were found to be poisonous. In 
general, the response given by the plants to the poisons resembled that 
given by animals, i.e., a very small amount of poison could be introduced 
into them without injury or noticeable change; a still larger amount in- 
creased their activities, often their growth; a larger amount retarded their 
activities, while still more killed. A plant could furthermore become 
accustomed to a poison to a certain limit, provided the poison was intro- 
duced into it in small quantities at first and these doses gradually were 
increased. Doses could in the end be administered without detriment that 
would otherwise have killed at once. 
The idea of injecting trees for purposes of wood preservation is also 
old. In 1840 and 1841, Boucherie (9) published accounts of experiments in 
which chemicals were injected into living trees. His method of injection 
killed the tree. The introduced liquid was distributed up and down the 
trunk, the injected area decreasing rapidly in breadth toward the roots. 
Fall was the best season for a complete saturation by this method, but it 
could be done in the spring. Coniferous trees were an exception because sap 
movement took place in them throughout the winter. Different substances 
were absorbed at different rates; neutral salts penetrated the wood in large 
quantities, acids and alkalies to a less extent. If there were hard knots or 
rotten spots at the base of the tree, the whole strip of wood above them 
would not be saturated at all. The same was true of the old wood of hard 
wood plants. Boucherie's ideas were used by Shevyrev in his work. 
The first paper on tree injection for purposes of medication was that by 
Ivan Shezyrez (J. Shevyrev, Schewirew or Chewyreuv) (10). The most of 
Shevyrev's experiments on the injection of living trees were made with 
stains for the purpose of establishing the fact that solutions of substances 
foreign to tree tissues could safely be introduced into trees. He mentions 
injecting grape vines with copper sulphate but does not give the results. 
He describes his methods of injection and his theories as to tree injection as 
follows : 
The best time for injection is the late summer and fall. The liquid is 
distributed to all parts of the tree, with the exception of the dead portions. 
The liquid enters the roots as well as the leaves, twigs, and fruits. This 
current takes the place of the sap, ascending and descending, the only dif- 
