Of recent years a considerable amount of work has been done in measuring the electrical resistance of spark gaps under different conditions. The subject is important, both for its application to wireless telegraphy and on account of its bearing on the mechanism of the spark gap. Spark spectra are, as is well known, more complex than arc spectra. Formerly this was attributed to a very high temperature in the spark, but it is now regarded as due to a disintegration of the atom produced in the spark gap. Or, as Baly puts it in his book on Spectroscopy, in the spark gap the atom is in a state of assisted radio-activity. If the current density in the spark gradually increases until it is strong enough to disintegrate a particular system in the atom, we should expect a new spectrum to be produced then, and probably a change in the resistance of the spark gap. My experiments have shown me that our methods of measuring the resistance of spark gaps are not nearly accurate enough to show such a change if it existed.