For satisfactory medical work with the X-rays, the first requisite is an efficient apparatus, the second, experience in examining a large number of cases.
It is impracticable in so short a paper to describe and compare the advantages and disadvantages of the various forms of static machines and coils that have been used to excite vacuum tubes, but T present photographs of the static machine I have been using at the Boston City Hospital for some time past, which give in themselves a sufficient idea of the machine and of my method of examining patients. The patients are brought to the X-ray room on a stretcher, that fits wooden horses placed in front of the machine, so that they are spared all possible fatigue. This machine has four revolving plates, six feet in diameter, and four fixed plates, six feet four inches in diameter. In Europe they are using coils