A device for the maintenance of a constant body temperature, with some special features

A device for the maintenance of constant body temperature of laboratory animals during experiments is presented. Some special features make it especially suitable for experiments in which small electrical events are to be recorded, because no 50 or 60 c/sec interference or spurious signals will occur from it, nor is the animal earthed through the apparatus. In 2 years of daily use it has proved to be a reliable and accurate working device.