from the plant cells after the death of the plant. These two factors the authors regard as the efficient cause of these changes in silage which have hitherto been attributed to the growth of bacteria, and they believe that bacteria have nothing to do with the process when it takes place in a normal manner.
The outcome of the experiments in growing Sumatra tobacco in the Connecticut Valley, recently reported by the National Department of Agriculture, is something more than a successful attempt at plant introduction. It is a tribute to the efficiency which has been attained in the methods of conducting soil survey, and a notable illustration of the scientific and practical value of such a survey as a basis for judging of the adaptation of agricultural plants. Two years ago the Division of Soils, in connection with its soil surveys in the Connecticut Valley, located areas about Hartford which it believed were suited to the growth of Sumatra tobacco. At that time it had never been grown in the region, and was not supposed to be adapted to it. During the past season the experiment was undertaken, in co-operation with the Connecticut State Experiment Station, on about a third of an acre. This was shaded from the sun by erecting a framework upon which cheese-cloth was stretched at a distance of about nine feet above the ground, and inclosing the sides as well. The tobacco grew well, and in due time was harvested and fermented as is customary. The quality of the finished product was pronounced excellent, and hardly to be distinguished from the imported article. As a substantial proof of this the crop has just been sold to a dealer at an average price of 71 cents per pound, including tops, butts and trash, along with the choicer leaves. As much as $1.25 per pound was received for some of the unsorted product. The average price received for the regular tobacco crop grown in the locality is about 20 cents. The Sumatra tobacco gave a net profit at the rate of nearly $900 an acre, exclusive of the expense of erecting the shade. The framework will last several years, but the cheese-cloth will have to be renewed each year. The object of shading this tobacco is to produce a thin leaf with small veins and a more luxuriant growth. Shading simulates the natural conditions under which it grows by making the atmosphere more humid and less subject to sudden changes. The Sumatra leaf is used for cigar wrappers, and is especially valued because it is elastic, free from objectionable taste and aroma, has small veins, which reduce the waste, and the leaf cuts up to better advantage than the ordinary wrapper leaf on account of its shape. About six million dollars' worth of Sumatra tobacco is imported annually, upon which a duty of $9,000,000 is paid. The experts in the Division of Soils estimate from their surveys that there is sufficient soil adapted to its growth in Connecticut and Florida to produce all that is demanded. This year's success will undoubtedly stimulate attempts to grow it regardless of the adaptation of the soil, so that there are likely to be many failures and disappointments another season, unless the advice of the Department is followed.
An interesting chapter has been added to the knowledge of the inert gases of the atmosphere by Dr. Ramsay, the co-discoverer of argon, and Dr. Travers. A little more than two years ago they announced the discovery of krypton and neon, and at the same time obtained indications of two other gases, to which they gave the names of met-argon and xenon. They now find that the presence of the so-called met-argon was due to carbon in the phosphorus used for removing the oxygen. By the use of large quantities of liquid air they have, by fractional distillation, obtained sufficient amounts of krypton and xenon to study their properties and measure their physical constants. They are all monatomic gases, and in their inertness completely resemble argon and helium. The spectra of these elements have been exam-
