. Contributions from the laboratory ... H. B. Hutchinson and N. TT. J. Miller 185 usual method, that of simply soaking the seeds in mcrciu-ic chloride solution, was found to he unsatisfactory owing to the persistence with which occasional air-bubbles rt-niain on or inside the seed, and thus prevent complete sterilisation. A greater amount of success was at- tained by subjecting the seeds to a preliminary treatment with ether or alcohol and subsequent transference to the disinfectant solution. The most satisfactory results, however, were obtained by treating the seeds in a warm mercuric chlorid
. Contributions from the laboratory ... H. B. Hutchinson and N. TT. J. Miller 185 usual method, that of simply soaking the seeds in mcrciu-ic chloride solution, was found to he unsatisfactory owing to the persistence with which occasional air-bubbles rt-niain on or inside the seed, and thus prevent complete sterilisation. A greater amount of success was at- tained by subjecting the seeds to a preliminary treatment with ether or alcohol and subsequent transference to the disinfectant solution. The most satisfactory results, however, were obtained by treating the seeds in a warm mercuric chloride soluti(m after the removal of any air-bubbles by means of a vacuinn pump; for this purpose the following apparatus was Fin. 1. A stout-Avalled glass flask B, bearing a rubber cork with two glass tubes, was attached on the one hand to a safety flask A, and on the other, by means of a three-way tube, to two glass flasks of about 1 litre capacity G and D. C was filled with a 0"25 per cent, solution of mercuric chloride, D with distilled water. The whole apparatus was then sterilised in the autoclave at 125° C. for half an hour, and after being allowed to cool to 40" C, the flask A was attached to a vacuum pump. Seeds of approximately equal size were then placed in the flask B by means of a funnel—to prevent contact between the seeds and the neck of the flask—and mercuric chloride was drawn by means of the pump into B from G. The connecting tube was then closed with a screw-clip and B was evacuated until the solution began to boil. By this means all air-bubbles present on the surface of the seed or between the cotyledons and the seed-coat were withdrawn, and on releasing the vacuum the disinfectant solution was able to act on all portions of the seed. Sterilisation was allowed to proceed for 3—4 minutes, and after B had been inverted and the disinfectant withdrawn by means of the. Please note that these images are extracted from scanned page images that ma
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