Human beings may be traced in almost any part of the globe through the tin cans which they leave behind them. Certainly, anywhere in North America where people have spent a day, there you may find this sign of their occupancy. To-day the retailer receives from the wholesaler the larger portion of his food supplies in a package, which is transmitted unbroken to the consumer. A grocery-store consists largely of a collection of original packages. Of all these sanitary devices, the tin can is probably the most significant and the most universal. Fruits, vegetables, meats and milk have all been subjected to the virtue of this humble container. Nicholas Appert, in France, first preserved food in glass jars by sealing them hermetically and heating. He published The Art of Preserving Animal and Vegetable Sub stances in 1811. In 1810 Peter Durand Obtained a patent in England for preserving fruits, vegetables and fish by hermetically sealing them in tin and glass cans. In 1820 William Under wood and Charles Mitchell, emigrant employees from a canning factory in England, Opened a factory in Boston where they canned plums, quinces, cranberries and currants. Glass was used exclusively until 1825, when Thomas Kensett secured a patent for use of tin cans and commenced to use them in his factory.