This text comes from The Canadian Soldiers' Song Book, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
Sing, sing, why shouldn't we sing?
Tho' days are dreary, let us be cheery,
Sing, sing! let melody flow,
For are the "Home Fires" out yet?
No, No, No, Sing, sing! why shouldn't we sing?
For there's one thing we never should forget;
Old John Bull is still alive and kicking
And we have'nt pull'd the blinds down yet: