Pieces of the True Cross were one of the most highly sought after of such relics; many churches claimed to possess a piece of it, so many that John Calvin famously remarked that there were enough pieces of the True Cross to build a ship from. A study in 1870 found that, put together, the claimed relics of the cross at that much later time weighed less than 1.7 kg. By the middle of the 16th century, the number of relics in Christian churches became enormous, and there was practically no possibility to distinguish the authentic from the falsification, since both of them had been in the temples for centuries and were objects for worship. In 1543, John Calvin wrote about fake relics in his "Treatise on Relics", in which he described the state of affairs with relics in Catholic churches. Calvin says that the saints have two or three or more bodies with arms and legs, and even a few extra limbs and heads.