ISDVSTRIrlL Ai\-D
June, 1928
ENGINEERI-\’G
of about 2 days in the time required for blooming, and reducing the strength of chemical to one-ninth delayed it about 7 days. Although this weakest strength delayed blooming as compared with the most favorable treatment, the gain in time of blooming as compared with the untreated plants was a t least 2 weeks. Treatment of Gladiolus Bulblets
The small bulblets or cormels used in propagating gladiolus are very dormant in the autumn and early winter. The slowness of germination and low percentage germinations obtained are sources of annoyance and financial loss to growers. It was found difficult to hasten the germination of these bulblets, a t least of the variety used, Halley; but by removing the outer husk and exposing the naked cormel to vapors of ethylene chlorohydrin a considerable gain was obtained. Figure 5 shows the results of one of these experiments. The three beakers a t the left show the lots treated with ethylene chlorohydrin and the three beakers at the right show the check lots, not treated, but planted the same day. I n this experiment nine different chemicals were tried, each chemical a t different concentrations, each concentration for different lengths of time. Only the chlorohydrin treatments were effective; the following chemicals did not give favorable results: ethylene, acetylene, acetaldehyde, chloroform, ethyl iodide, furfural, thiourea, sodium nitrate. The chlorohydrin treatments consisted (1) in exposing the cormels for 3 days to vapors in a closed container, using 0.5 cc. of 40 per cent chlorohydrin per liter of space; or (2) dipping the cormels into a solution made by mixing 100 cc. of 40 per cent chlorohydrin with 900 cc. of water, and storing the dipped cormels 6 days in a closed container. Discussion of Chemicals
From the standpoint of cost, treatments with these chemicals are commercially feasible. The cost of chemicals for
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treating potatoes with either sodium thiocyanate or ethylene chlorohydrin should not exceed 5 or 10 cents per bushel. I n the original article describing the effect of thiourea in inducing multiple-bud f ~ f m a t i o n ,it~ was stated that the high cost of this chemical would preclude its use for commercial purposes. It has since been found, however, that this chemical is now available at a price that would make its use feasible if the results of the treatment should be found to be satisfactory under practical conditions. The cost of treating potted woody shrubs with ethylene dichloride or ethylene chlorohydrin will depend upon the size of the plants-i. e., upon the number of plants that can be put into the room used for gassing. The cost should not be more than a few cents per plant; in experiments a t this laboratory with plants 3 to 4 feet high in 12inch pots the cost has been about 2 cents per plant. Another question that needs consideration is whether the chemicals are dangerous to human beings, either because of poisonous or explosive properties. Sodium thiocyanate is poisonous, but it is not believed that the small quantities that might accidentally te taken into the system by the workmen who are treating and planting the potatoes would be injurious. If the potatoes after treatment are properly protected from animals, and if the liquid residues are properly disposed of, there should be no danger. In the case of ethylene chlorohydrin the question as to whether the vapors can form an explosive mixture with air must also be considered. The writer attempted to obtain explosions by mixing various amounts of the vapor in closed containers and sparking the mixture with a spark-plug connected to an automobile. All tests were negative. It is believed that there is no danger of explosions with chlorohydrin vapor a t ordinary temperature. The writer has not yet been &le to obtain information as to the explosiveness of ethylene dichloride under such conditions. In experiments in this laboratory mixtures of this vapor with air have been protected from electric-motor sparks and from flames.
Maple Sap and Its Improvement’ Edward Hart LAFAYBTTECOLLEGE, EASTON, PA.
B U L L E T I N S 103, 151, and 1 6 i of the Vermont Agricultural Station contain many interesting particulars concerning the sap obtained from the maple tree. Bulletin 103 was printed in 1903. At that time the six states, Vermont, New York, Ohio, Michigan, Pennsylvania, and New Hampshire, named in the order of their output, furnished 95 per cent of the sugar and 80 per cent of the sirup made. Vermont furnished from one-fourth to one-third of the maple-sugar products. I n ordinary practice the maple sap contains from 2 to 3 per cent sugar, and it is obvious that too much water must be evaporated from the sap to allow of an economical production of saccharose. It would be quite impracticable to produce any sugar if that from maple sap were not salable a t a higher figure than that obtained from the cane and beet. In 1918 I bought a farm in eastern Pennsylvania within a mile of the Delaware. Part of this farm consisted of neglected woodland. Following the advice of the chief forester, I began clearing out the dead and fallen timber as well as those trees unlikely ever to yield logs of good quality, and in their place planted other trees, mostly white pine. I t occurred 1
Received March 22, 1928.
to me that I might as well have a sugar bush and some three hundred sugar maples were planted, but on discovering the low yield of sugar likely to result I felt discouraged and planted no more sugar maples. On further reflection I was unable to see that such a low yield was necessary, believing it was due to a lack of seed selection. Further examination of available data confirmed this view. Inasmuch as the yield of the sugar beet has been increased in this way from 6 to 16 per cent, it would seem probable that a similar procedure with the sugar maple would give like results. The time required to bring this about, however, would be very much greater and the parties working with this improvement in view could never reasonably expect to get any return whatever for their exertions. A committee has been formed of the faculty of Lafayette College consisting a t present of three members who, together with their successors, are pledged to carry this work to completion. That it can be done we are hopeful, for Harvey JT. Wiley has recorded a tree on his father’s farm which gave a yield of nearly 5 per cent sugar, and the Bulletin 103 quoted gives, on page 122, an account of a “sweet tree” which gave on one occasion a yield of as high as 8.20 per cent.
