Short answer. Yes. Article 1494 gives you, as the buyer of specific goods that had already perished in part, or deteriorated so much they changed materially in character, the option to treat the entire sale as avoided. You may instead choose to keep the undamaged portion and pay the agreed price for it, if the sale can be divided.
What the law says
the buyer may at his option treat the sale: (1) As avoided; or (2) As valid in all of the existing goods or in so much thereof as have not deteriorated, and as binding the buyer to pay the agreed price for the goods in which the ownership will pass, if the sale was divisible.
Civil Code, Article 1494 — Partial Loss of Specific Goods. Read the full provision →
The choice belongs to the buyer
Article 1494 applies where the parties intended to sell specific, identified goods, and part of that specific stock had, without the seller's knowledge, already perished or deteriorated so seriously that its character was substantially changed by the time of the sale. In that situation, the law does not force a result on either side. It gives the buyer the option: you may treat the whole sale as avoided, or you may accept it as valid over whatever goods still exist undamaged, so long as those two choices are genuinely available on the facts.
Avoiding the sale entirely
If you choose to treat the sale as avoided, you are not bound to accept or pay for any part of the goods, including the portion that survived intact. This option makes sense where the loss goes to the heart of what you bargained for, where the surviving goods alone would not serve your purpose, or where you simply prefer not to proceed once you learn part of what you thought you were buying no longer exists as agreed.
Keeping the undamaged part instead
Alternatively, Article 1494 lets you treat the sale as valid over the goods that still exist and have not deteriorated, provided the sale was divisible, meaning it can reasonably be split into the surviving portion and the lost or damaged portion. If you take this route, you must pay the agreed price for the goods you keep and that ownership passes to you. This option suits a buyer who still wants what remains, at a proportionate price, rather than losing the transaction altogether.
What this depends on
This protection is tied to specific goods, meaning particular, identified items rather than goods generally described and yet to be selected, and to loss the seller did not know about when the parties struck their bargain. Whether the sale can actually be divided into a surviving and a lost portion, and how the price should be apportioned if you keep only part, depends heavily on the terms of your particular agreement and the nature of the goods involved.