Letter perfect

Stroke by stroke the language was slipping away from him. My dear nephew, he had written in his clear miniscule hand, I am sorry, though not, of course, surprised, to hear of your financial woes. And I am far from deaf to the eloquence of your arguments. (There was charity for you, he thought. His nephew on paper was like a cow on tiles.) I have long been aware that the economic climate in the dairying regions is nezther Invigorating nor, shall we say, sal- ... Damn! What was that word? Salub-? Solubr-? ... It was too vexing . ... neither invigorating nor healthy he concluded irritably.