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312 will light instantly on being struck, but that will behave itself at other times. Forms of potash and of manganese mixed with phosphorus help to make better and safer matches. The very best matches of all are the "safeties," that cannot be lighted anywhere except on the sand panel on the box. That is because the phosphorus is not on the match head but on the panel.

Another thing that makes safety matches safe is that red phosphorus is used. That is the most expensive, but the cheaper kinds of phosphorus are poisonous. For this reason their use in matches has been prohibited in the United States and most of the countries in Europe. Matches made from these white or yellow phosphoruses were not only very poor things, and dangerous to have about the house, but the workmen who made them were poisoned. They got a disease that softened the bones. Nowadays we think a good deal about the way in which other people are treated, and the conditions under which they have to work. The result is that not only have laws been passed prohibiting the use of poisonous kinds of phosphorus in matches, but we now have matches containing substitutes for the yellow phosphorus, which will strike anywhere. One of these substitutes is known as semi-sulphide of phosphorus—a combination of phosphorus and sulphur. The name is almost as long as the match, isn't it?