The Interferometer Method in the Diagnosis of Pregnancy and Malignant Conditions

Abstract

Paul Hirsch was the first to develop a method which appeared to give strictly quantitative results in using the Abderhalden reaction with small quantities of serum. By an ingenious modification of the chamber of the Lowe interferometer as made by Zeiss he was able to use very small quantities of serum for testing the digestive breakdown of specific substrates by means of a specific serum. As one is able with this instrument to detect differences of refractive index to the seventh decimal place, while the ordinary refractometer does not give results better than to the fifth place in decimals, it is seen that the advance made by Hirsch in this direction was a considerable one. The method at once attracted much attention, and was taken up by a very large number of workers. Hirsch has recently published a bibliography in which no less than 75 communications are mentioned, where the method has been used. Most of these workers have come to favorable conclusions as to its usefulness. It has been used for detecting pregnancy in animals and women, for ascertaining the presence and degree of endocrine disturbance and expecially for diagnosing gastric and intestinal inflammation and conditions due to malignant growths.