A. R. Kolli.

(Obituary).

The small family of Russian physicists has suffered a grievous loss. In Rostov-on-Don, during the civil war, Professor A. R. Kolli of Warsaw University was killed. By origin Kolli was an Englishman, the son of the former professor R. A. Kolli, known for his works in the field of electricity (the classical theory of induction belongs to him). After finishing gymnasium in Moscow, Kolli entered the Faculty of Physics and Mathematics of Moscow University, and already in the last years of his student life he undertook in the laboratory of Prof. P. A. Umov certain investigations in the field of electromagnetic waves. A. R. Kolli began his independent work after graduating from the University, becoming interested, at the suggestion of P. N. Lebedev, in the then widely debated study of the dispersion of electromagnetic waves in pure substances and their mixtures. This work, begun first in P. A. Umov’s laboratory, was then transferred during Kolli’s foreign assignment to Göttingen, where Kolli worked in Nernst’s laboratory; here he entered into the circle of those workers who were grouped around the physics colloquium and in which such scholars as W. Voigt, J. Stark, and M. Abraham took part. Kolli and Voigt preserved friendly relations thereafter, and Voigt highly valued the young scholar’s talent. Kolli then continued the study of dispersion in R. Drude’s laboratory in Berlin, where he remained until Drude’s tragic death. During this time he completed a very extensive and highly careful work, whose aim was to develop a methodology for investigating and studying pure liquids with regard to their refractive index for electromagnetic waves. These works, first printed in Russian in the journal of the R. Phys.-Chem. Soc., were, at Voigt’s insistence, translated by one of his pupils into German and reprinted in the Physikalische Zeitschrift.

The principal results obtained by Kolli consisted in the fact that he succeeded in revealing with complete clarity the existence of a spectrum of a substance in the region of electromagnetic waves of about 30 cm in length, and in showing that the structure of this spectrum is influenced by the molecular groups composing parts of the molecule of the substance, just as they influence the structure of the infrared spectrum.

Upon returning to Russia, Kolli received an offer from Prof. N. P. Kasterin to take the position of privat-docent in Odessa, and, after a short stay there and after defending a doctoral dissertation, to which he was admitted without a master’s examination and without a master’s dissertation, Kolli was elected professor in Warsaw, where in a short time he succeeded in excellently organizing a laboratory,

to surround himself with collaborators and to organize a colloquium. To this same period belong Kolli’s remarkable investigations on the dispersion of waves in mixtures of liquids, which led him at the Second Mendeleev Congress to speak of the possibility of photochemical reactions in the electromagnetic spectrum. At the same time Kolli made an attempt to create a school, and two of his pupils, Obolensky and Ivanov, already have works dealing with the same field in which Kolli himself worked.

An unusually talented lecturer, Kolli always knew how, even in the most popular lectures, to approach a question in a completely scientific way; and all who heard him vividly remember his brilliant lectures in the commercial classes, where, despite the limited preparation of the audience, all of physics in its modern form was presented with perfect clarity to beginners.

In the laboratory Kolli knew how to attract young people to himself, and in recent times 5–6 people were always working with him. In the last years before the war Kolli worked out in great detail the plan for a Physical Institute in Warsaw, but the war did not allow him to complete this work, which would have enabled him to organize scientific research more broadly.

P. Lazarev.