There is a grammarians' rule that it is wrong to write and which (and similar expressions such as and who, and where, but which, or which, etc.) except by way of introducing a second relative clause with the same antecedent as one that has just preceded it. According to this rule, Nelson was wrong grammatically, as well as in other more momentous ways, when he wrote to Lady Nelson after his first introduction to Lady Hamilton:
She is a young woman of amiable manners and who does honour to the station to which he has raised her.
To justify the and who grammatically a relative is needed in the first part of the sentence, for example,
She is a young woman whose manners are amiable and who ...
Conversely, the writer of the following sentence has got into trouble by being shy of and which:
Things which we ourselves could not produce and yet are essential to our recovery.
Here which cannot double the parts of object of produce and subject of are. To set the grammar right the relative has to be repeated:
Things which we ourselves could not produce and which are ...
The rule is subject to many exceptions and complications. Fowler has nine columns on it. Those who observe it in the simple form in which it is stated at the beginning of this section may at least be sure of not offending the purists. But they will do still better if they resolve to avoid the inevitable clumsiness of and which, even when grammatical. Thus these two sentences might be written:
She is a young woman of amiable manners who does honour to the station to which he has called her.
Things essential to our recovery which we ourselves could not produce.