Section 241. Coal in quantities of one hundred pounds or less shall be sold by weight, and coke and charcoal in quantities of one hundred pounds or less shall be sold by weight or measure, in bags, sacks or baskets, and until delivered shall be kept in the same bags, sacks or baskets in which they were weighed or measured; and coal, coke and charcoal thus sold shall be exempt from section two hundred and forty-four. When sold by weight, such bags, sacks or baskets shall be plainly marked with the name and business address of the person who puts up the same, and with the weight of the coal, coke or charcoal therein in letters and numerals, respectively, of bold uncondensed type at least one inch in height. Coal that is packaged in any manner in advance of sale at retail shall be plainly and conspicuously marked with the name and business address of the person who puts up same, a statement of the net weight of the coal contained therein, a classification of such coal whether anthracite, semi-anthracite, bituminous containing less than twenty-three per cent volatile matter or bituminous containing more than twenty-three per cent volatile matter, and the size of the coal contained therein.