What is the case law on cruelty in the context of desertion and desertion?

In Waters v. Waters [1956] P 344, at 362-3, [1956] 2 WLR 661, Wallington, J. is reported as follows: “The misdirection to which, in my view, their judgment was due, has been fully dealt with by my Lord in his judgment; and all I desire to say about it is that in my opinion the justices regarded it as essential to the wife’s case on cruelty that they should be satisfied that there has been a wilful and deliberate intention on the part of the husband to be cruel to his wife, and as to the desertion, they apparently thought that the wife must prove a deliberate intention on the part of the husband so to act as to drive her away from the matrimonial home. “In my view that was erroneous. A man may be cruel to his wife, especially perhaps in mental cases, if he says to himself, and acts upon what he says: ‘Now I am going to be physically and otherwise cruel to my wife. I will do this or that to her, and I intend to hurt her;’ or he may be cruel to his wife (especially, as I repeat, in mental cases), if he says to himself and acts upon what he says, ‘I am going to live my own life in my own way, whatever the consequences to my wife,’ and if day after day he does the kind of thing which he must know would have a serious effect upon her health—and in this case upon the evidence, it may be said that the justices might have found that he knew, because there is evidence that the wife told him so —in either of these classes of acts, if proved, with proof also of danger or reasonable apprehension of danger to the life, limb or health, bodily or mental, of the wife, a case of cruelty might, in my opinion, be made out.”