This auction is for a Vintage Metal Cello Sanitary Hot Water Bottle Patented on Nov 26, 1912.  It was made by the A. S. Campbell Co. in Boston.  This hot water bottle is made of metal >> it is not attracted to a magnet, so I think this is nickel.  Overall, it is very good condition >  the plug is still in the bottle, there are no holes.  Over 100 years old.