North America

Nano-sized P25TiO₂NPs were kindly donated by Dr. Scaiano, Ottawa University (Canada). Riboflavin (vitamin B2) was from Sigma and ascorbic acid (vitamin C) and KBr (for IR pills) were from Cicarelli. Base cream for the animal experiments was purchased from Todo Droga and the LED panel was built ad hoc.

Lithopone or sulphide of zinc white has been in general use for twenty years or more in many industries where a white pigment of considerable body or hiding power is required that is not subject to change like lead carbonate and has not the brittle character of zinc oxide, besides being sold at a lower figure than either of these. Nevertheless it is still comparatively new to the general painting trade. Because of our tariff protection its manufacture in this country has made great progress. Yet in spite of this and the duty imposed on it, the imports are still in excess of the quantity manufactured here. A short history of its origin will no doubt prove of interest to our readers.