"But I have not told you half our troubles yet," he answered mischievously. "Thus far I have spoken only of the cocoons. In addition there is the water to consider. That must be the right sort, too. It must be as pure as we can get it, both chemically and in color. And even then the high temperature necessary to bring the silk off the cocoons will cause any sandy sediment there may be in it to rise to the surface and cut the filament as we reel it off. We have to be prepared for that emergency as well as the others. And now to return to the sorting of the cocoons. Do you see that pile over there? Those are what we call perfect ones. The thread from them will go into the finest quality silks and satins, as the filament has neither spots nor flaws." "But those cocoons are very small," objected Pierre. "Yes. The best cocoons are not always the largest, by any means. It is quality, not size, that counts." Henri passed on. "Here now," he continued as he paused before another lot, "are some more pointed at one end than at the other. We know from bitter experience that they will reel badly, because the silk which runs smoothly at the beginning will prove to be weak in some places and break. We toss them aside and reel them separately. These _cocalons_, as we call this other kind, are also thrown out because they are hard to wind." "They are much larger," observed Pierre. "You are right. Nevertheless they have no more silk on them. The reason they look bigger is because the worm spun them less compactly; unless they are put into cold water they will tangle and mat when reeled." "And that next lot?" "_Soufflons_? They are the most imperfect cocoon made. The silk is so loosely spun that it cannot be wound at all, and is good only for floss." Pierre shook his head despairingly. "I thought I knew quite a lot about cocoons," he said. "But by the time I go home I shall feel I don't know anything. Why, I never could learn to sort all those kinds if I kept trying for years." "Only those who have handled thousands of cocoons can," returned his guide consolingly. "I couldn't begin to do it. Here is a pile now! They have a hole in the end and cannot be reeled because every time the thread comes to the perforation it is broken. Probably the moth was allowed to escape and injured the filament. They must be used for floss, too, for they are good for nothing else." The boys wandered on down the room.