A hundred ten years ago this month, the April 1909 issue of Popular Electricity carried this ad for the Diozo Phone Disinfector, produced by the Parker Chemical Co. of 233 Market Street, Chicago.  (The address no longer exists, since Market Street disappeared and became part of Wacker Drive.)

The ad, confirmed by scientific tests, warns that the mouthpiece of every telephone swarms with malignant germs, including tuberculosis, diphtheria, typhoid, or pneumonia.  There might even be more revolting diseases lurking there!  Fortunately, to avoid the harm, all you need to do is slip the diozo phone disinfector on the mouthpiece.  Diozo is apparently a disinfectant that works in its solid form to somehow kill germs.

But according to this article published just a few months later in the California State Journal of Medicine, the State Hygenic Laboratory (of California, presumably) questioned some of the claims made by the company.  After being challenged, the company noted that to be effective, the Diozo must be crushed and mixed with water, which would make its use on a telephone somewhat problematic.

Strangely enough, the Diozo Phone Disinfector doesn’t appear to be available today.  But if you search Amazon for “phone disinfector,” you can chose among the following products: