For serologic work a constant temperature water-bath is a necessity, and a bath heated and controlled by electricity has manifest advantages over any other kind. While there are several electric water-baths on the market, they are not entirely satisfactory, either because the size is excessive in comparison with the available working space, or because the regulating and heating attachments are cumbersome and in the way. A bath made according to our specifications appears to overcome these objections. Modifications as to size, but which will still retain the more important features of the bath, may suggest themselves.
The bath illustrated in Figure 1 was designed to carry two metal test tube racks, each measuring 8¾ by 4 inches and 2¾ inches in height, and each with a capacity of forty-eight tubes of the 3 by ⅜ inch size, as shown in Figure 2. These racks are suspended by adjustable supports