An Introduction to Chemical Science

reak Gla

be broken, till a scratch is made. Take the tube in the hands, having the two thumbs nearly opposite the scratch, and the fingers on the other si

a blunt iron-in a blast-lamp flame by preference-till it is red-hot, and at once press it against the scratch till the glass begins

ke Igniti

g it as the glass softens. The yielding is detected by the yellow flame above the glass and by an uneven pressure on the hands. Pull it a little as it yields, then heat a part just at one side of the most softened portion. Rotate constantly without twisting, and soon it can be separated into two closed tubes. No th

ed out with illuminating gas. This gives a high degree of heat. Bulbs can be made in the same way as igniti

end Glas

id twisting, and be sure to have all parts in the same plane; also avoid bending too quickly, if you would have a well-rounded joint. Anneal each bend as made. Heated glass of any kind should never be brought in contact with a cool body.

o Cut

or a guide, and pressing down hard enough to scratch the glass. Then break it by holding between the thumb and fingers, having the thumbs o

with a broken end of a round file kept wet wi

Perfora

the left hand and pressing against the larger surface, or upper part, of the cork, with the file in the right hand. Only a mere opening is made in this way, which must be enlarged by the other end