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New measurements of stellar radiation
April, 1,)22.1
U . G . BUREAU OF CHEMISTRY NOTES.
557
V I A B I L I T Y OF T H E C O L O N - T Y P H O I D GROUP IN CARBONA T E D W A T E R A N D C A R B O N A T E D BEVERAGES.* By $. A. Koser and W. W. Skinner. [ABSTRACT.]
CARBONATION exerts a distinctly h a r m f u l effect upon the m e m bers of the colon-typhoid group, the period of viability of which is much s h o r t e r in carbonated w a t e r than in plain tap water. T h e destructive effect of the carbon dioxide is especially m a r k e d at r o o m t e m p e r a t u r e (19 to 23 ° C.) ; it is tess m a r k e d at I ° C. T h e o r g a n i s m s m a y persist for a slightly longer period in a " non-acid " beverage than in carbonated water. I n beverages containing 0.094 per cent. or m o r e of citric o,r lactic acids, the death-rate is v e r y rapid, being due apparently to the effect of these two acids. Bact. typhosum and Bact. paratyphosmu B are m o r e readily destroyed by carbon dioxide than is Bact. coll. T h e spore f o r m s o,f a c o m m o n aerobe, B. mesentericus, and of a c o m m o n anaerobe, Clost. sporogenes, proved to be quite resistant to carbonation, s u r v i v i n g for one m o n t h at r o o m temperature with no apparent diminution in numbers. N e w M e a s u r e m e n t s of S t e l l a r R a d i a t i o n .
W . W . COBLENTZ.
(Astrophys. J., Jan., I 9 2 2 . ) - - T h e s e measurements were carried out at the Lowell Observatory, Flagstaff, Arizona, with the use of a vactmm thermo-couple and confirm certain conclusions derived from observations made at the lower altitude of the Lick Observatory. I f a red star and a blue star appear to be of the same magnitude, the red star emits from 2.5 to 3 times as much total radiation as the blue one. I f three stars, respectively blue, yellow and red, emit the same amount of total radiation, then the blue star emits twice as much visible radiation as the yellow star and three times as much as the red one. By means of transmission screens the distritmtion of energy in the spectra of I6 stars was determined. The percentage of stellar energy transmitted through a layer of water one cm. thick was measured. These are some of the results: Rigel, 63; Castor, 82; Sirius, 65; Capella, 57; Aldebaran, 42; Betelgeuse, 34. The blue stars emit a smaller amount of infra-red radiation than do red stars of the same apparent magnitude. G. F. S. "Published in J. Bact., 7 ( 1 9 2 2 ) VOL. I93, No. II56---39
:
III-I2I.
358
CURRENT TOPICS.
[J. F. I.
At the meeting of the French Physical Society on December 16, I92i , A. Perard reported on progress made with the quartz standards of length recommended by the International Committee on Weights and Measures. These are square prisms, 25 mm. on a side with the .edges parallel to ~he crystallographic axis. Th.e length embodied by each prism is not the distance between two cross lines but the distance between the two accurate and parallel planes forming the ends. T w o interference methods based on Michelson's arrangement are used to measure the length. It is not necessary to silver the ends of the prism. By one of these methods prisms of the several lengths, I, 2, 4, IO and 2o ram., have been measured. In the discussion which followed the paper Professor F a b r y directed attention to the difficulty of obtaining satisfactory sources of monochromatic light for metrological purposes. Commercial mercury vapor lamps are durable and convenient, but unfortunately each line has satellites. The cadmium tube to produce the red X - r a y in the wave-length of which standard lengths are now expressed is not only fragile but has to be made in the labo.ratory. Neon gives lig~h.t that will prove of use in accurate measurements and its commercial applications make it easy to get. The rays of krypton are exceptionally sharp, but this gas is hard to obtain in France. The construction of tubes filled with this gas would have little or no practical value, but, on the other hand, would be of distinct scientific advantage. G. F. S. R a d i u m for E n g l a n d . (Science, Oct. 21, I 9 2 I . ) - - F r e d e r i c k Soddy, professor of chemistry in Oxford, visited the Joachimsthal mines in Czecho-Slovakia and inspected them thoroughly, seeing also the processes for extracting radium from the pitchblende. On his return he brought with him to England two grams of radium, valued at ~7o,ooo. The transportation of so large a mass of this substance was not an easy matter in view of the constant emission of particles at enormous velocities. The radium was divided up between nine glass phials placed within a case of lead three inches thick and Doctor Soddy travelled as a King's Messenger. Upon his arrival his precious burden was deposited in the Foreign Office. The owner of the radium, The Imperial and Foreign Corporation of London, has an agreement with the Czecho-Slovakian government by which it gets the loan of the radium output of the mines for a period of fifteen years, less an amount reserved for public use. The state will continue to work the mines. The Corporatio n expects to make use of its recent importation thus: " The radium will be lent freely for hospital purposes, and rented out to private practitioners. It will also be used for the production and sale of radio-active water in bottles, for use at radiosanatoria, the production and sale of radio-active fertilizers, and for its by-products, such as polonium." G.F.S.
U . G . BUREAU OF CHEMISTRY NOTES.
557
V I A B I L I T Y OF T H E C O L O N - T Y P H O I D GROUP IN CARBONA T E D W A T E R A N D C A R B O N A T E D BEVERAGES.* By $. A. Koser and W. W. Skinner. [ABSTRACT.]
CARBONATION exerts a distinctly h a r m f u l effect upon the m e m bers of the colon-typhoid group, the period of viability of which is much s h o r t e r in carbonated w a t e r than in plain tap water. T h e destructive effect of the carbon dioxide is especially m a r k e d at r o o m t e m p e r a t u r e (19 to 23 ° C.) ; it is tess m a r k e d at I ° C. T h e o r g a n i s m s m a y persist for a slightly longer period in a " non-acid " beverage than in carbonated water. I n beverages containing 0.094 per cent. or m o r e of citric o,r lactic acids, the death-rate is v e r y rapid, being due apparently to the effect of these two acids. Bact. typhosum and Bact. paratyphosmu B are m o r e readily destroyed by carbon dioxide than is Bact. coll. T h e spore f o r m s o,f a c o m m o n aerobe, B. mesentericus, and of a c o m m o n anaerobe, Clost. sporogenes, proved to be quite resistant to carbonation, s u r v i v i n g for one m o n t h at r o o m temperature with no apparent diminution in numbers. N e w M e a s u r e m e n t s of S t e l l a r R a d i a t i o n .
W . W . COBLENTZ.
(Astrophys. J., Jan., I 9 2 2 . ) - - T h e s e measurements were carried out at the Lowell Observatory, Flagstaff, Arizona, with the use of a vactmm thermo-couple and confirm certain conclusions derived from observations made at the lower altitude of the Lick Observatory. I f a red star and a blue star appear to be of the same magnitude, the red star emits from 2.5 to 3 times as much total radiation as the blue one. I f three stars, respectively blue, yellow and red, emit the same amount of total radiation, then the blue star emits twice as much visible radiation as the yellow star and three times as much as the red one. By means of transmission screens the distritmtion of energy in the spectra of I6 stars was determined. The percentage of stellar energy transmitted through a layer of water one cm. thick was measured. These are some of the results: Rigel, 63; Castor, 82; Sirius, 65; Capella, 57; Aldebaran, 42; Betelgeuse, 34. The blue stars emit a smaller amount of infra-red radiation than do red stars of the same apparent magnitude. G. F. S. "Published in J. Bact., 7 ( 1 9 2 2 ) VOL. I93, No. II56---39
:
III-I2I.
358
CURRENT TOPICS.
[J. F. I.
At the meeting of the French Physical Society on December 16, I92i , A. Perard reported on progress made with the quartz standards of length recommended by the International Committee on Weights and Measures. These are square prisms, 25 mm. on a side with the .edges parallel to ~he crystallographic axis. Th.e length embodied by each prism is not the distance between two cross lines but the distance between the two accurate and parallel planes forming the ends. T w o interference methods based on Michelson's arrangement are used to measure the length. It is not necessary to silver the ends of the prism. By one of these methods prisms of the several lengths, I, 2, 4, IO and 2o ram., have been measured. In the discussion which followed the paper Professor F a b r y directed attention to the difficulty of obtaining satisfactory sources of monochromatic light for metrological purposes. Commercial mercury vapor lamps are durable and convenient, but unfortunately each line has satellites. The cadmium tube to produce the red X - r a y in the wave-length of which standard lengths are now expressed is not only fragile but has to be made in the labo.ratory. Neon gives lig~h.t that will prove of use in accurate measurements and its commercial applications make it easy to get. The rays of krypton are exceptionally sharp, but this gas is hard to obtain in France. The construction of tubes filled with this gas would have little or no practical value, but, on the other hand, would be of distinct scientific advantage. G. F. S. R a d i u m for E n g l a n d . (Science, Oct. 21, I 9 2 I . ) - - F r e d e r i c k Soddy, professor of chemistry in Oxford, visited the Joachimsthal mines in Czecho-Slovakia and inspected them thoroughly, seeing also the processes for extracting radium from the pitchblende. On his return he brought with him to England two grams of radium, valued at ~7o,ooo. The transportation of so large a mass of this substance was not an easy matter in view of the constant emission of particles at enormous velocities. The radium was divided up between nine glass phials placed within a case of lead three inches thick and Doctor Soddy travelled as a King's Messenger. Upon his arrival his precious burden was deposited in the Foreign Office. The owner of the radium, The Imperial and Foreign Corporation of London, has an agreement with the Czecho-Slovakian government by which it gets the loan of the radium output of the mines for a period of fifteen years, less an amount reserved for public use. The state will continue to work the mines. The Corporatio n expects to make use of its recent importation thus: " The radium will be lent freely for hospital purposes, and rented out to private practitioners. It will also be used for the production and sale of radio-active water in bottles, for use at radiosanatoria, the production and sale of radio-active fertilizers, and for its by-products, such as polonium." G.F.S.