Communicating by Patronus (Was: Harry’s new Patronus)

[justcarol67]

No: HPFGUIDX 137702

Carol earlier:
<snipped> 
> > We've only seen animal Patroni but that doesn't mean a Patronus
*has* to take animal form. (Absence of evidence is not proof.) I see
no reason why it can't be a person. Suppose that Snape's Patronus 
> turns out to be Dumbledore? Think how much *that* would give away, >
especially if he's still able to cast it after killing Dumbledore 
> <snip> A Patronus is white magic. The fact that Snape can (or could)
cast one suggests to me that he really is on the side of good--or was
until he fell under the curse of the DADA position and made the
Unbreakable Vow. 
> 
> 
> J responded:
> 
> If I remember, JKR was asked about this in an interview. Someone 
> said, what form is Snape's patronus? Here's the quote:
> 
> I wonder if you can let us know what form will Professor Snape's 
> Boggart and Patronus take? I am very curious.
> JK Rowling replies -> Well, I'm not going to tell you Ernie, but 
> that's because it would give so much away.
> 
> A lot of people take that to mean that its a phoenix or dumbledore 
> or something like that. Now, I don't necessarily believe this 
> myself, but it could just be because someone as evil as Snape can't 
> cast a Patronus, it being a very white-magicy type of spell.


Carol responds:
Yes, that was the quote I had in mind when I wrote the earlier post,
but I take it to mean that he *can* cast a Patronus and that its form
 will reveal his true allegiance. (It can't be a phoenix, which was
DD's Patronus, but it could be Dumbledore or even, as I half-seriously
proposed in the earlier post, a dumbledore = bumblebee. It can't be
some evil creature, which would be a contradiction in terms, not to
mention a dead giveaway that he was not to be trusted.) 

And if he couldn't cast a Patronus at all, wouldn't that in itself
arouse Dumbledore's suspicions? He's the one who taught the Order
members how to use their Patroni to communicate. The Order members
would also know that he couldn't cast a Patronus and must therefore be
a Dark Wizard. And how would he communicate with them under normal
circumstances, letting them know he's on his way to headquarters or
whatever? He can certainly receive messages from a Patronus--Tonks'
new Patronus delivered the message to him rather than to Hagrid, as
she intended, clearly indicating that it recognized him as an Order
member.

Which brings me to the question of how a Patronus can be used to
deliver a message. It's not like an owl, which can deliver a whole
letter. The messages sent by Patronus, which are sent quickly by a
single flick of the wand, must be very short, reflecting a single
thought: "Escort Harry to the school" or "Come to the forest at once"
(DD to Hagrid in GoF). 

To go off track for a moment, I think Snape in OoP must have used the
fireplace in Umbridge's office rather than a Patronus to communicate
with the Order once he had cured the Inquisitorial Squad of their
minor hexes and discovered what was going on. (Sorry, Neri. I still
think that's what caused the delay in OoP. And then he seems to have
gone into the forest himself to look for Harry, causing further
delay.) As Pippin has pointed out, it's not an instantaneous form of
communication. You can't conduct a conversation using one. Yet Snape
seems to have directly told Sirius not to go to the MoM and that
Dumbledore was coming (maybe he sent a Patronus to Dumbledore to
determine that), and he would have had to explain why he thought Harry
had gone to the MoM, however improbable it seemed since Harry could
neither apparate nor use a broom (and the Floo network was blocked).
All of that seems to detailed and complex to communicate by Patronus,
especially since he'd have had to wait for an answer. Which is not to
say that Snape can't cast a Patronus (as I've already indicated, the
inability to cast one would be a dead giveaway that he was not loyal
to Dumbledore), only that it would not have been the best method of
communication in this particular situation.

To return to the topic, how does the Patronus, which is usually an
animal, carry the message? Does a scroll bearing the Order member's
thoughts magically appear, to be carried in the animal Patronus's
mouth, and disappear into thin air once it's been read? Or can a
Patronus speak? Also, it seems to be sent to a *place* rather than a
person. Otherwise, Snape could not have read a message intended for
Hagrid. And if a Patronus is white magic (as JKR confirms that it is),
would it have delivered the message to him if he weren't genuinely on
the side of the Order?

Carol, who can't get her mind off Snape but is still interested in how
a Patronus carries a message and how complex such a message could be