Page:Popular Science Monthly Volume 55.djvu/737

Rh on what takes place near the shore. In other words, it is difficult to destroy marine life, so far as fish are concerned, by mischief done near the coast. Their area of propagation and reproduction is too large for land creatures like us, who can only invade the sea in boats, seriously to injure it." Yet the experiments and experience of the United States Fish Commission show that we are able to increase the supply immensely.

Relative Power of Fungicides.—Mr. F. L. Stevens has published, in the Botanical Gazette, an account of experiments made for the purpose of establishing with some degree of accuracy the strengths of various solutions which are necessary to prevent the growth of fungous spores. The bearing of this question upon the relation of a fungicide to its efficiency is apparent. As among the general results the author finds that mercuric chloride is the strongest chemical used in its toxic effect upon the fungi, while potassium cyanide is remarkably weak considering its great toxic action on animals. Alcohol and sodium chloride have a stimulating effect. Various fungi offer different resistance to poisons, and the limits of resistance will vary in the same species. The spores of fungi are less susceptible than the roots of seedlings. A chemical may be twice as powerful as another against one fungus, while in acting upon another fungus an entirely different ratio may be sustained. An occasional spore may germinate and grow quite normally in a solution that prevents hundreds of normal spores around it from germinating. Penicillium as a nutrient medium offered greater resistance to poisons than did any of the other fungi worked upon. Uromyces did not diminish in vigor of growth with the increased strength of the poison, but the percentage of spores that germinated was diminished. In general, the results of the action of the chemicals were in accord with the theory of hydrolytic association. Incidentally new evidence bearing upon the theory of the hydrolytic dissociation of the molecule was adduced, together with facts that may throw some light upon the structure of the cell wall.

National Forest Reserves.—The report of the Secretary of the Interior for the year ending June 30, 1898, mentions thirty forest reservations (exclusive of the Afognac Forest and Fish-Culture Reserve in Alaska) as existing by presidential proclamation under the act of March 3, 1891, embracing an estimated area of 40,719,474 acres. The patrolling of the reserves has shown that fire is the paramount danger to which they are exposed. Next to fire, sheep-raising is the most serious difficulty to be considered in administering the reserves. Yet, as it is not considered expedient to prohibit so important an industry throughout the reserves, special efforts have been directed toward ascertaining the particular regions in which the conditions demand the exclusion of sheep, and toward learning what restrictions may be necessary in other regions. The institution of a national system of timber cutting to be economical in all directions is under consideration, but it is acknowledged that the work will require a certain degree of experience and training on the part of forest officers. A forest system inaugurated by the department in August, 1898, in which the reserves are placed under the control of a graded force of officers, has already shown good results; the reports received from the forest officers indicate that the patrolling has limited both the number and extent of fires. During the eighteen months previous to the preparation of the report in November, 1898, a great advance was made toward a comprehensive administration of the public forests. A marked change in public sentiment toward forest policy is noticed, with a subsidence of the opposition to the reserves and a tendency among the people in the localities directly interested to take a deep and approving interest in the matter.

Sloyd as an Educational Factor.—Mr. Gustaf Larsson, of the Sloyd Training School, Boston, represents, in his Bulletin, that Sloyd is steadily gaining ground, and has been introduced, during the past year, into city schools, colleges, and charitable institutions, and that many clubs and social organizations are becoming interested in it as an educational factor. The Sloyd principles seem to meet a cordial welcome wherever they are adequately presented. Mr. Larsson insists that in Sloyd instruction the teacher should enter into the child's