Effects of particle size, crystallinity and the amount of the structural water in kaolinites on their infrared spectra, were studied. The samples were ground in a vibrating ball-mill, and infrared and X-ray spectra, as well as thermal and specific surface area measurements, were taken on the initial and ground samples. Changes of the 3705-cm−1 infrared band intensity and of the absorbance ratio of the A 3630/A 3705-cm−1 bands were determined as a function of the grinding time. Correlation functions between the absorption ratio, calculated from the infrared spectra, and the average particle size, as well as between the amorphism, calculated from the X-ray spectra, and the average particle size, were obtained.

Infrared spectra of two minerals; Urkut quartz (Hungary) and a Swedish feldspar, of different origin with different physical characteristics and crystallinity were studied. Samples were taken after appropriate grinding, and infrared spectra, X-ray powder diffraction and water vapor absorption measurements were made along with electronmicrographs. Quantitative conclusions were drawn from changes of particle size and the ratio of bands of the Si—O groups and also the degree of crystallinity and changes of the particle size, respectively.

A serological study of cytomegalovirus infection in London shows it to be prevalent. Under 5 years of age only 4% of children have antibodies, but this increases to 15% by 10 years of age and 21% by 15 years. The maximum incidence of 54% is reached by 25–35 years, and this is maintained in the older age groups of the population. In two mixed day schools the incidence of infection was significantly lower than in a boarding school, suggesting that close prolonged contact is required for spread of infection.

Different strains of cytomegalovirus possess common group-specific complement-fixing antigens.

It is suggested that clinical disease caused by cytomegaloviruses is more frequent and more varied than previously believed, although diagnosis may be difficult without virological help.