confirmed relation (3), i.e., that the log of the sputtering time is, within sufficiently wide limits, linearly related to \(\log c\). The thickness of his films King estimates from optical data at \(1—6\,\mu\mu\); the temperature influence was not studied by him.

King’s theory only supplements Stearn’s theory, establishing a certain functional dependence; it does not, however, explain the negative value of the temperature coefficient and does not permit one to conclude, as the author does, that the conductivity of thin films is often metallic in character. Equation (5) indicates only that \(C\) is a certain statistical function of \(N\), while the statistical elements may be both King’s metallic chains and Stearn’s “interstices”; in other words, the validity of equation (5) merely confirms the granular structure of the film.

The condensation of metal molecules into molecular complexes may occur, according to King’s supposition, in the space between the cathode and the glass plate. It is possible, however, that precisely the surface of the plate is the determining factor in the formation of grains.

C. Vasiliev.

On the shunt method of measuring receiving strength.

(Van der Pool. Philos. Mag. September 1917).

When measuring very weak currents in an antenna one has to use a telephone shunted by a variable resistance, and as a measure of the current strength one takes the “audibility factor” introduced by Hogan,

\[ \frac{R+S}{S}, \]

where \(R\) is the resistance of the telephone, and \(S\) is the resistance of the shunt at which the signals disappear. Hogan (Electrician IX-Xi p. 720, 1913) assumes that this quantity is approximately proportional to the square of the current strength \(J\) in the antenna.

Love (Philosophical Transactions vol. CCXV A p. 105, 1915), considering observations on the strength of the current in an antenna during long-distance telegraphy, made by Hogan and Austin, found that they agree well with the theoretical conclusions of Macdonald and Love if one assumes that

\[ \frac{R+S}{S} \]

is proportional to the current strength \(J\) for small values of it, and to \(J^2\) for large values.

In the article named in the heading, van der Pool reports the results of his laboratory study of this question.

He took two circuits: in circuit I, representing the antenna, oscillations were excited; in circuit II, weakly coupled with I, a shunted telephone was included. The quantity

\[ \frac{R+S}{S} \]

was determined at various distances of circuit I from II, whereby the same effect was obtained as if the current strength in antenna I were varied. The magnitude of the current strength was not measured, but was calculated by the formula of Maxwell Rosa. The results confirmed Love’s supposition: for values of

\[ \frac{R+S}{S} \]

from 4 to 160, \(\frac{R+S}{S}\) is proportional to \(J^2\),

for values from 1.2 to 4, \(\dfrac{K+S}{S}\) is proportional to \(J\). These conclusions are of considerable interest for measuring the strength of reception, since the square of the current strength is usually taken to be proportional.

Gerasimov.

Does a Sub-Electron Exist?

(Millikan. Die Existenz eines Subelektrons? Ann. d. Phys. 1916, 50 p. 729.)

At the present time the number of methods for determining the ratio of charge to mass, \(\dfrac{e}{m}\), and separately \(e\) and \(m\), can be brought up to twenty. Some of them (for example, electrolysis, the deflection of \(+\) and \(-\) rays in electric and magnetic fields) are direct; others (for example, the Zeeman effect, dispersion) must be classed as indirect. It should be noted that the method of dispersion, by means of which many determinations have been made, generally speaking admits several solutions and, for example, Loria’s measurements give for the dispersion constant

\[ a=\frac{Ne^2\lambda_0^2}{\pi mc^2} \]

a value 200 times smaller than that calculated theoretically.

Ehrenhaft, Millikan, and Ioffe use a specially developed method for determining the elementary electric charge in small metallic or other drops falling in an electric field and separating from themselves free electrons under the influence of energy incident upon them (for the apparatus see, for example, A. Ioffe, Beobachtungen über den photoel. Elementareffekt, Sitzungsber. der Bayer. Akademie 1913). But while Millikan and Ioffe obtained for the elementary quantum a value established earlier (ca. \(4\cdot 10^{-10}\) cgsk), Ehrenhaft, as a result of a similar investigation (Über die Quanten der Elektrizität. Der Nachweis von Elektrizitätsmengen, welche kleiner sind als das Elektron, Wien 1914), arrives at a much smaller (20–30 times) value of the charge, \(e=1.4\text{—}2.8\cdot 10^{-11}\) cgsk, which he calls the sub-electron. In the article named in the heading, Millikan subjects Ehrenhaft’s conclusions to sharp criticism. He asserts that in all cases where the experiments do not give rise to any doubts: 1) ions carry a charge equal to or exactly a multiple of the Elementarquantum \(4\cdot 10^{-10}\) cgsk; 2) static charges, preserved and separated from insulators or conductors, obey the same rule; 3) direct tearing away of a negative electron from a “particle” or “drop” by the Millikan–Ehrenhaft–Ioffe method causes a change in charge equal to the charge of an ion in electrolysis. Millikan explains the deviations of the Elementarquantum from the normal value, which led Ehrenhaft to assert the existence of the sub-electron, by false assumptions concerning the density and spherical form of his particles. At the present time, in his opinion, there is no evidence whatever for the existence of the sub-electron.

In any case, this question requires further investigations and the establishment of an exact constant for \(e\), especially in connection with recent work in theoretical physics (if only for the question of the dependence of the mass of the electron on velocity. See, for example, Kasterin, “On the Inconsistency of Einstein’s Principle of Relativity,” Izv. Ross. Akademii nauk, 1918, No. 2–3).

V. V. Ilyin