From Chapter VI of Manuel Garcia Jr's New Treatise on the Art of Singing:

First.—The pupil should gently and slowly inhale for a few seconds, as much air as the chest can well contain.
Secondly.—After taking a deep breath, the air should be exhaled again very gently and slowly.
Thirdly.—Fill the lungs, and keep them inflated for the longest possible time. And,
Fourthly.—Exhale completely, and leave the chest empty as long as the physical powers will conveniently allow.

Try on your own, and let me know if you have any questions!

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