Although not pendants in the traditional sense, since they were painted for different patrons, it is argued here that Carle Van Loo's 'A pasha having his mistress's portrait painted' and 'The Grand Turk giving a concert to his mistress, shown at the Salon of1737, were meant to be read as a pair - as portraits of the artist and his wife and as allegories of Painting and Music. By linking the paintings, Van Loo may have intended them to make a statement on the changing relations between art and patronage.

In this study, mechanical-electrical transformations were excited in heterogeneous solid materials. Electromagnetic signals were excited in rock samples via determined acoustic pulses. The main patterns of changes in the electromagnetic signals' amplitude–frequency parameters at the contacts of the rock samples with distilled and mineralised water were determined. We find that contact with distilled water decreases the electromagnetic signal and spectral component amplitudes, while contact with brine leads expands the spectrum. The laws determining the changes in the parameters of the electromagnetic signals and their spectra in porous sandstone samples saturated with water or salt solutions are given. Based on our results, a method is proposed to quantify the salinity of natural water contained in oil or other sources based on changes in the electromagnetic signal parameters when such water comes into contact with rocks.