PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR

Ernest Sturm; Frederick L. Gates; James B. Murphy

doi:10.1084/jem.55.3.441

PROPERTIES OF THE CAUSATIVE AGENT OF A CHICKEN TUMOR

Journal of Experimental Medicine ◽

10.1084/jem.55.3.441 ◽

1932 ◽

Vol 55 (3) ◽

pp. 441-444 ◽

Cited By ~ 13

Author(s):

Ernest Sturm ◽

Frederick L. Gates ◽

James B. Murphy

Keyword(s):

Spectral Analysis ◽

Incident Light ◽

Common Factor ◽

Ultra Violet ◽

Biological Cells ◽

Spectral Absorption ◽

Violet Light ◽

Chemical Character ◽

Coefficients Of Absorption ◽

Tumor Agent

Even though part of the energy of the incident light is probably absorbed by chemical entities which play no part in the specific reaction of inactivation, nevertheless the wave lengths most active in destroying biological cells or agents will presumably be found to be among those absorbed in the highest proportion. This would indicate that the curves here presented are approximately reciprocal to the coefficients of absorption of particular substances, the destruction of which caused the inactivation of the agents or the death of the cells. The similarity between the curves for bacteria, virus, and phage, both in shape and in total involved energies, suggests the presence of a common factor, or of closely related chemical entities, sensitive to ultra-violet light, whereas the data for the tumor agent suggest that its inactivation is due to the destruction of a substance having an essentially different spectral absorption, and therefore of a different chemical character. While the amount of ultra-violet energy required to affect the tumor agent is great, it is still less than that involved in the inactivation of some of the enzymes (7). A study is under way to compare the deduced spectral analysis with the actual coefficients of absorption of the highly purified tumor agent.

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PHYSICAL, CHEMICAL, AND BIOLOGICAL STUDIES ON THE VIRUS OF VESICULAR STOMATITIS OF HORSES

Journal of Experimental Medicine ◽

10.1084/jem.45.6.969 ◽

1927 ◽

Vol 45 (6) ◽

pp. 969-981 ◽

Cited By ~ 7

Author(s):

Peter K. Olitsky

Keyword(s):

Foot And Mouth Disease ◽

Ultra Violet ◽

Taxonomic Study ◽

Violet Light ◽

Physical Chemical ◽

Biological Studies ◽

Chemical Constitution ◽

Vesicular Stomatitis ◽

Chemical Character ◽

Generic Connection

A taxonomic study of the virus of vesicular stomatitis is presented along with evidence additional to that already reported1 to show the similarity of this virus to that of foot-and-mouth disease. The connection of the two is discussed and the deduction drawn that their generic relationship is close. On the contrary, the differences between these two viruses and the herpetic are sufficiently marked to indicate a lack of generic connection among the three. The results of a comparative study on the effects of particular wave-lengths and energies of monochromatic ultra-violet light on the virus and on Staphylococcus aureus reveal that the adsorption of specific energies by the two is parallel. Since the adsorption of specific energies is an index of chemical character, these experiments suggest that the virus is similar in character and chemical constitution to bacterial protoplasm.

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VII. On the emission velocities of photo-electrons

Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character ◽

10.1098/rsta.1913.0007 ◽

1913 ◽

Vol 212 (484-496) ◽

pp. 205-226 ◽

Cited By ~ 39

Keyword(s):

Experimental Evidence ◽

Incident Light ◽

Wave Length ◽

Ultra Violet ◽

Metallic Surfaces ◽

Quantitative Evidence ◽

Maximum Emission ◽

Violet Light ◽

Decisive Test ◽

Electric Effect

Since the discovery of the photo-electric effect by Hertz, many experiments have been made on the emission of negative electricity from metallic surfaces when illuminated by light. Yet with regard to many important points the results are often indefinite and contradictory. Most theories of the photo-electric effect indicate definite relations between the velocity of emission of the electrons and ( a ) the nature of the metal from which they are emitted, and ( b ) the wave-length of the incident light. Up to the present, however, the experimental evidence as to these two relations must be regarded as quite inadequate to afford any decisive test between rival theories. This research was undertaken to obtain, among other things, quantitative evidence on these two relations. 2. Previous Work .— Ladenburg made some valuable experiments on the velocity with which electrons are emitted from metals when illuminated by ultra-violet light. He concluded that the maximum emission velocity was inversely proportional to the wave-length. The velocity varied from metal to metal; thus, for light of wave length λ 2010, the maximum emission velocity (measured in volts) for platinum was 1·86 volts, and for zinc 1·12 volts. The source of light used by Ladenburg was a mercury arc. His metals were polished with emery and oil, and were exposed to the atmosphere for some time before the apparatus for measuring the velocity could be exhausted.

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