After the plaintiff discovered that his sale of a threshing machine to the defendant was legally ineffective, he received an award at trial for the estimated value of the defendant's use of the machine until it was returned to him, namely, $60, being $10 for each day the machine was used. He appealed on the matter of costs - either his claim sounded in damages, or he was restricted to costs determined by the "small debt scale."
The Court found that the plaintiff's claim sounded in damages. Lamont J.A. stated (at DLR p. 95):
In Corpus Juris, vol. 1, at p. 966, the distinction between the old action of assumpsit and that of debt is made as follows:
"As ordinarily stated, the distinction between assumpsit and debt is that the former is to recover damages for the breach of a simple or parol contract, and the latter for the recovery of a debt, eo nomine and in numero; that assumpsit will lie where the amount is uncertain or unliquidated, and debt only for a sum certain."
...
A sum is considered certain when it can be made certain. By this, I take it, is meant where it can be determined by computation. If, for instance, the contract of the parties furnishes a specific mode or rule of payment, or if its terms furnishes the means of ascertaining the exact amount due, an action for debt will lie. But where no specific sum is claimed, and neither the contract nor the averments furnish data from which the defendant can determine the amount he owes, the action, in my opinion, cannot be said to be for a "debt" ... .