Natural weapons with multi-turn touch attack spells

Question

Some spells use touch attacks to deliver their effects to the target. For many of these (like shocking grasp), the touch attack is discharged the first such time that happens. These clearly fall under this rule here:

Holding the Charge: If you don't discharge the spell in the round when you cast the spell, you can hold the charge indefinitely. You can continue to make touch attacks round after round. If you touch anything or anyone while holding a charge, even unintentionally, the spell discharges. If you cast another spell, the touch spell dissipates. You can touch one friend as a standard action or up to six friends as a full-round action. Alternatively, you may make a normal unarmed attack (or an attack with a natural weapon) while holding a charge. In this case, you aren't considered armed and you provoke attacks of opportunity as normal for the attack. If your unarmed attack or natural weapon attack normally doesn't provoke attacks of opportunity, neither does this attack. If the attack hits, you deal normal damage for your unarmed attack or natural weapon and the spell discharges. If the attack misses, you are still holding the charge

Others have specific language about how they interact with combat. Elemental touch is one such spell:

You gain a melee touch attack causing 1d6 points of damage of that energy type, along with a special effect described below. You also deal energy damage and the related special effect when you attack with your hands using an unarmed strike, a single claw, or a single slam attack. This bonus damage can never apply to multiple weapons.

So my question involves spells that grant touch attacks over a duration without a discharge, like disable construct:

You can make a melee touch attack to send a pulse into the target, interfering with the magic that endows it with life.

(essentially, spells with range: touch that are some duration other than instantaneous without special language that explicitly outlines their behavior)

Can natural attacks be used to make "free" touch attacks with spells of this type, the same way as in the "Holding the Charge" clause (even if this isn't "holding" the charge, per se, since the spell is not instantaneous duration)? If so, can that happen only once per turn, or with every natural attack (if the creature has more than one)?

Answer 1

Only once per casting. Disable construct is a touch spell and uses exactly the same "Holding the charge" rules as other touch spells.

The duration stated in the spell refers to the number of assaults the helpless effect lasts. You do only perform one touch attack after casting the spell. Then, either the attack is successful and the spell discharges on the touched target or the attack fails and you hold the charge normally.

Answer 2

Chill touch is a spell that allows several uses instead of just holding one charge, so that is a spell that fits your topic, but from your question my answer might be off-topic. Chill touch, once cast, can be delivered 1/CL. For example if you are 10th level you cast it once and then you can use it to deliver the effect up to 10 times. And this can be through touches or natural attacks.

If you just wanted to know if you had it right with disable construct forget my answer, the comment by Hey I Can Chan and the answer by Balcertar cleared that up already.

Answer 3

The spell calcific touch matches the situation you described. I'm no authority, but I believe it has been ruled that calcific touch can be delivered via natural attacks. Generalized, I guess that means you should be able to deliver touch spells via natural attacks; though the free touch attack you get on the round you cast the spell is just that; a single touch attempt, not a natural attack attempt.

This thread is a discussion of calcific touch and how it works in general, including with natural attacks. The author of the spell got involved, so his comments can be taken as RAI for that spell.