This is the hard to find number 4 Gilbert Micro Chemistry set from the company known for their iconic Erector sets. The idea was to conduct the chemistry experiments from the included 64-page "Chemistry For Boys" booklet, then study them under the 50 power microscope. The book is really thorough, with instructions for 150 different experiments plus much more information.

The set appears to be mostly complete, though some of the chemical containers have been opened (four or five are unused). There are glass slides, litmus paper, metal spoon and measure, tweezers, slide covers, glass test tubes, and the microscope with its own instruction book. Other non-original items found in the box include pencils, rulers, pencil leads, and a bubble glass magnifier. The booklets have copyright dates of 1935 and 1936.