WE have received from Messrs. Boots Pure Drug Co., Ltd., Nottingham, an illustrated booklet describing the preparation and uses of Insulin-Boots. The insulin is extracted from frozen pancreas glands by mincing into an alcoholic solvent; further treatment of the solution is necessary to remove the bulk of the inactive protein. The resulting clear solution is concentrated at low temperature by vacuum distillation. After removal of fat the insulin is precipitated by addition of salt and further purified by fractional precipitation in the iso-electric range and from various solvents. The booklet describes the tests to which each batch is submitted, the properties of insulin and its use in diabetes and in non-diabetic conditions. A useful section is a detailed account of the technique of subcutaneous injection. Insulin-Boots is issued in three strengths, 20, 40 and 80 units per c.c.