BOTANY. 953 



The wheat was allowed to mature, after which the soil?, grain, and straw were 

 analyzed. It was found that the sulphuric acid content of the soils was increased, 

 doubtless due to the oxidation of the sulphurous acid. The growth of the plants 

 was not interfered with where there were present in the soil bases, such as lime or 

 magnesia, with winch the sulphurous acid could combine. The sulphuric acid con- 

 tent of the cereal, especially that of the straw, increased in proportion to the sul- 

 phuric-acid content of the soil. 



The experiments with the zinc compounds were carried on in a similar manner to 

 those described above. It was found that the addition of as much as 0.235 per cent 

 of zinc oxid was without effect on the plants. The lime content of the soil was 

 found to exert no influence on the action of the zinc oxid, and there was no increase 

 noticed in the zinc content of the plants. 



Where zinc sulphate was added to the soils it proved highly injurious to the wheat 

 plants and the injury was not reduced to any extent by the application of large 

 amounts of lime. 



Injury to vegetation by smelter fumes, J. K. Haywood ( U. 8. Dept. Agr., 

 linn an of Chemistry />'"/. 89, ////. 23, pis. 6, fig. 1). — The results are given of investiga- 

 tions made to ascertain the extent of injury inflicted on surrounding vegetation by a 

 copper smelting plant located near Redding, Cal. After describing the general 

 character of the region, the location of the smelter, and the appearance of the vege- 

 tation the author discusses the chemical principles underlying the investigation. 



The ore used by the smelting company consists largely of sulphids of iron and 

 copper, and the impurities are either fluxed or burned off. This results in the pro- 

 duction of a large amount of sulphur dioxid and to some extent sulphur trioxid. 



Experiments were conducted to test the visible injury by sulphur dioxid, in which 

 potted plants were subjected for various lengths of time to different proportions of 

 sulphur dioxid in the atmosphere. The effect of this treatment on the foliage and 

 the results of analyses of the leaves are given, after which the analyses of foliage 

 collected about the smelter are given and comparisons drawn between the two series 

 of analyses. 



The author also summarizes the results of a number of other investigations on the 

 injury to vegetation by smelter fumes, and from his investigations draws the follow- 

 ing conclusions: 



"Sulphur dioxid when present in very small quantities in the air kills vegetation. 

 Such injury shows itself by the increased sulphur trioxid content of the foliage. The 

 vegetation around the smelter for at least Z\ miles north, 9 miles south, 2i miles 

 east, and 5 to 6 miles west has been greatly injured. The water of the Sacramento 

 River is polluted by the waste material from the smelter. It is the opinion of the 

 author that this injury to vegetation will continue and even increase its limits unless 

 the fumes are condensed. The fumes can be condensed and sulphuric acid formed, 

 for which a ready market would probably be found." 



The absorption of electromagnetic waves by living vegetable organisms, 

 G. 0. Squibb {San "Francisco, 1904, pp. S2, pis. 4, figs. 3). — In connection with a 

 report on investigations of wireless telegraphy carried on for the War Department, 

 the author gives an account of some phenomena suggested by the action of trees as 

 conductors for electromagnetic oscillations. The experiments were carried on princi- 

 pally in the vicinity of San Francisco, a grove of eucalyptus trees being utilized as 

 the receiving station. 



The apparatus and method of experiment are described, and it is said that the trees 

 were found to serve as a substitute for the towers and masts usually required to carry 

 the antennae wires. The investigations showed that the trees were capable of receiv- 

 ing and giving off the electric current required in wireless telegraphy, and marked 

 differences in efficiency were noted with different species of trees, such as willow, 

 pine, spruce, oak. etc. A tree with a small leaf surface and in an unhealthy con- 



