In Lally v. Kuster (1918) 177 Cal. 783, the plaintiff employed an attorney to collect an overdue note and mortgage, but the collection action was dismissed by the court over four and one-half years later due to lack of diligent prosecution. Regarding the plaintiff's burden in the subsequent malpractice action, the state high court quoted from Corpus Juris as follows: " 'In a suit by a client against an attorney for negligence in conducting the collection of a claim, whereby the debt was lost, the burden rests on the former to allege and prove every fact essential to establish such liability. He must allege and prove that the claim was turned over to the attorney for collection; that there was a failure to collect; that this failure was due to the culpable neglect of the attorney, and that, but for such negligence, the debt could, or would, have been collected. Hence, where a claim is alleged to have been lost by an attorney's negligence, in order to recover more than nominal damages it must be shown that it was a valid subsisting debt, and that the debtor was solvent.' " ( Id. at pp. 787-788.)