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The ejection of protons from nitrogen nuclei, photographed by the Wilson Method
.fQvL1925.1
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existing thing, he should not be permitted to patent such an improvement with a view of deriving extraordinary benefit from something which he was definitely employed to do. It may be desirable to take out patents in a case of the sort in order to prevent designing people from securing patents for their own benefit on certain features of the work and thereby defeat the very object of the work. The publication of articles and reports,‘which are of necessity general in their presentation, cannot be depended upon to act as an anticipation in the same way that a patent does, and there is, therefore, considerable risk that once the general results of a research are known, designing people will endeavor to secure patents on some of the features. Where patents are taken out on an improvement of the sort a definite arrangement should exist with the research worker by which the patent can be made public either by dedication by the inventor or by the research foundations which provided the facilities. Where the problem is a general investigation of a large mass of phenomena, or where the research worker is working on a problem of his own making, then, if in connection with such an investigation he makes an invention which may have come to his mind merely as an incident to his general work, he should have the right to patent the invention as his own, Even though this feature may be an embarrassing one which may call for a number of special rulings, I firmly believe that in general there should be no restriction put on the worker respecting the patenting of anything he may develop, and that any feature of an investigation that can be patented should be patented because, if this is not done, some unprincipled person may endeavor to take advantage of the opportunity to secure a patent of his own. Research foundations may be made useful in avoiding as far as possible the duplication of research, but an attempt should not be made to go too far in directing research. To secure the .best results an ambitious worker must have a free hand and it is this type of worker that should be given encouragement and assistance. The Ejection of Protons from Nitrogen Nuclei, Photographed by the Wilson Method. P. M. S. BLACKETT. (Proc.Royal SOC., A 74a.)-Rutherford and Chadwick have shown that rapidly moving
a-particles under certain conditions can eject protons from the nuclei of light elements. The author desires to learn how the three bodies
254
CURRENT
TOPICS.
[J. F. I.
concerned, the nucleus, the proton and the particle, comport themselves after the disastrous collision. The scintillation method can detect the proton alone, but the others have too short a range to register their arrival by a flash of light on the screen. The cloud1 method of C. T. R. Wilson, however, can furnish information concerning all three bodies. There will be but few cases at best in which protons will be projected from nuclei, in fact, ~,ooo,ooo a-particles of 8.6cm. range will give rise to only about twenty such cases in nitrogen. Accordingly a Wilson apparatus was devised, making an expansion and taking a photograph of the tracks every ten or fifteen seconds. About 23,000 photographs were taken of tracks in nitrogen. “The average number of tracks on each photograph was 18; the of 8.6-cm. range and 145,000 tracks of about 270,000 a-particles of 5-cm. range have therefore been photographed.” These numbers are rather appalling, yet among the vast number of collisions recorded only eight differed1 greatly from the rest. “ These eight tracks undoubtedly represent the ejection of a proton from a nitrogen nucleus. It was to be expected that the photograph of such an event would show an alpha-ray track branching into three. The ejected proton, the residual nucleus from which it has been ejected, and the alpha-particle itself, might each have been expected to produce a track. These eight forks, however, branch only into two.” The proton leaves a fine, straight track, while the second branch resembles the track of a nitrogen nucleus. There is no third branch. “ On the generally accepted view, due to the work of Rutherford, the nucleus of an atom is so small, and thus the potential at its surface so large, that a positively charged particle that has once penetrated1 its structure (and almost certainly an alpha-particle that ejects a proton must do so) cannot escape without acquiring kinetic energy amply sufficient to produce a visible track. As no such track exists, the alpha-particle cannot escape. In ejecting a proton from a nitrogen nucleus the alpha-particle is therefore bound to the nitrogen This conclusion is confirmed by quantitative study of nucleus.” G. F. S. the effects observed. Notes on Neodymium Oxide. E. L. NICHOLS. (Proc. Nat. 1925.)-Neodymium oxide is interesting Acad. Sciences, Jan., because it gives a discontinuous spectrum though it is a solid. The light from it, provided its temperature is not much above 1000’ C., “ At higher stages of incandescence the bands shows six bands. merge and the spectrum cannot be distinguished from that of a *black In order to get the band spectrum a body of like temperature.” hydrogen flame must impinge on the oxide. Another peculiarity of the substance is that at about goo’ it is brighter than a black body “ At the above temperature, therefore, there of the same temperature. is luminescence of the oxide superimposed’ upon the incandescence.” G. F. S.
STIMULATION
OF RESEARCH.
253
existing thing, he should not be permitted to patent such an improvement with a view of deriving extraordinary benefit from something which he was definitely employed to do. It may be desirable to take out patents in a case of the sort in order to prevent designing people from securing patents for their own benefit on certain features of the work and thereby defeat the very object of the work. The publication of articles and reports,‘which are of necessity general in their presentation, cannot be depended upon to act as an anticipation in the same way that a patent does, and there is, therefore, considerable risk that once the general results of a research are known, designing people will endeavor to secure patents on some of the features. Where patents are taken out on an improvement of the sort a definite arrangement should exist with the research worker by which the patent can be made public either by dedication by the inventor or by the research foundations which provided the facilities. Where the problem is a general investigation of a large mass of phenomena, or where the research worker is working on a problem of his own making, then, if in connection with such an investigation he makes an invention which may have come to his mind merely as an incident to his general work, he should have the right to patent the invention as his own, Even though this feature may be an embarrassing one which may call for a number of special rulings, I firmly believe that in general there should be no restriction put on the worker respecting the patenting of anything he may develop, and that any feature of an investigation that can be patented should be patented because, if this is not done, some unprincipled person may endeavor to take advantage of the opportunity to secure a patent of his own. Research foundations may be made useful in avoiding as far as possible the duplication of research, but an attempt should not be made to go too far in directing research. To secure the .best results an ambitious worker must have a free hand and it is this type of worker that should be given encouragement and assistance. The Ejection of Protons from Nitrogen Nuclei, Photographed by the Wilson Method. P. M. S. BLACKETT. (Proc.Royal SOC., A 74a.)-Rutherford and Chadwick have shown that rapidly moving
a-particles under certain conditions can eject protons from the nuclei of light elements. The author desires to learn how the three bodies
254
CURRENT
TOPICS.
[J. F. I.
concerned, the nucleus, the proton and the particle, comport themselves after the disastrous collision. The scintillation method can detect the proton alone, but the others have too short a range to register their arrival by a flash of light on the screen. The cloud1 method of C. T. R. Wilson, however, can furnish information concerning all three bodies. There will be but few cases at best in which protons will be projected from nuclei, in fact, ~,ooo,ooo a-particles of 8.6cm. range will give rise to only about twenty such cases in nitrogen. Accordingly a Wilson apparatus was devised, making an expansion and taking a photograph of the tracks every ten or fifteen seconds. About 23,000 photographs were taken of tracks in nitrogen. “The average number of tracks on each photograph was 18; the of 8.6-cm. range and 145,000 tracks of about 270,000 a-particles of 5-cm. range have therefore been photographed.” These numbers are rather appalling, yet among the vast number of collisions recorded only eight differed1 greatly from the rest. “ These eight tracks undoubtedly represent the ejection of a proton from a nitrogen nucleus. It was to be expected that the photograph of such an event would show an alpha-ray track branching into three. The ejected proton, the residual nucleus from which it has been ejected, and the alpha-particle itself, might each have been expected to produce a track. These eight forks, however, branch only into two.” The proton leaves a fine, straight track, while the second branch resembles the track of a nitrogen nucleus. There is no third branch. “ On the generally accepted view, due to the work of Rutherford, the nucleus of an atom is so small, and thus the potential at its surface so large, that a positively charged particle that has once penetrated1 its structure (and almost certainly an alpha-particle that ejects a proton must do so) cannot escape without acquiring kinetic energy amply sufficient to produce a visible track. As no such track exists, the alpha-particle cannot escape. In ejecting a proton from a nitrogen nucleus the alpha-particle is therefore bound to the nitrogen This conclusion is confirmed by quantitative study of nucleus.” G. F. S. the effects observed. Notes on Neodymium Oxide. E. L. NICHOLS. (Proc. Nat. 1925.)-Neodymium oxide is interesting Acad. Sciences, Jan., because it gives a discontinuous spectrum though it is a solid. The light from it, provided its temperature is not much above 1000’ C., “ At higher stages of incandescence the bands shows six bands. merge and the spectrum cannot be distinguished from that of a *black In order to get the band spectrum a body of like temperature.” hydrogen flame must impinge on the oxide. Another peculiarity of the substance is that at about goo’ it is brighter than a black body “ At the above temperature, therefore, there of the same temperature. is luminescence of the oxide superimposed’ upon the incandescence.” G. F. S.