_Insulin now available for everyone._--Insulin can now be obtained in every drug store and fortunately, thanks to wise provisions for maintaining control of its manufacture arranged for by the University of Toronto, it is everywhere of uniform strength. This matter of constant strength is of the greatest importance. As will appear later, danger attends its indiscriminate use, and the dose must be made to match the amount of sugar derivable from the diet. Unless the strength of various lots of insulin is constant, accurate treatment would be impossible. This was recognized early by the workers in Toronto and, to protect the public, it was decided that insulin must be patented so that its manufacture could be restricted to those firms who would permit the control of their products by an insulin committee in Toronto. The firm of Eli Lilly and Company of Indianapolis put their plant at the disposal of the insulin committee and assisted in developing methods of large scale production. Subsequently, other firms have been licensed, by the insulin committee, to make insulin. * * * * * The patenting of discoveries by physicians is usually frowned on by physicians. It is opposed to the ethical code of the profession. The patenting of insulin, however, does not violate this ethical code because the patent, while secured in the name of Doctor Banting and his associates, was given outright by them to the University of Toronto to be used, not for any commercial advantage, but as a means to guarantee that this splendid discovery would not be exploited by others to its discredit. _Insulin described._--Today, insulin, as sold, is a clear, watery solution. A small vial contains 50, 100 or 200 units, as indicated on the label. The strength of the unit is standard. A unit of insulin will have a certain definite lowering effect on the sugar in the blood of a normal animal. The rabbit is chosen as the test animal. In the patient with diabetes, a unit of insulin will increase tolerance, that is, it will add to the amount of sugar that can be utilized, from 0.5 gram to 4 grams, depending on the character of the diet and the presence or absence of complications. The average patient uses between 10 and 30 units a day. The cost has been reduced to below one cent a unit, so that insulin is now brought within the reach of everyone. Indeed, the cost is negligible when we consider that patients who, without insulin, were helpless invalids, dependent on relatives or charity, are now as fit and strong as their neighbors, and able to work again. THE CAUSE OF DIABETES