Lowing soap bubbles with hydrogen
Mix up a strong soap solution that will make good soap bubbles. Place a small funnel tube or a clay pipe on the delivery tube. When you have a good action of acid and zinc in the flask, blow bubbles with the hydrogen. When every bubble has been formed a slight jerk will detach it from the funnel and it will increase to the ceiling. You can have a lot of fun trying to light the bubbles by placing a lighted candle on the end of a stick to arrive at them near the ceiling