Newlands discovered that if he listed the elements in ascending order of their atomic weights, in vertical lines of seven, the properties of the elements along the corresponding horizontal lines were remarkably similar. As he put it: "In other words, the eighth element starting from a given one is a kind of repetition of the first, like the eighth note in an octave of music." He named this his "law of octaves." In the tabulated list the alkali metal sodium (the 6th heaviest element) stood horizontally beside the very similar potassium (13th heaviest). Likewise, magnesium (10th) was in line beside the similar calcium (17th). When Newlands expanded his table to include all the known elements he found that the halogens, chlorine (15th), bromine (29th) and Iodine (42nd), which exhibited graduating similar properties, all fell in the same horizontal column. Whereas the trio of magnesium (10th), silenium (12th) and sulphur (14th), which also had graduating similar properties, fell in the same vertical line. In other words, his law of octaves also seemed to incorporate the scattered resemblances noted in Dobereiner's law of triads.