In the necklace, what did Monsieur Loisel want to buy with the money he gives to Mathilde

Monsieur Loisel's is eager and willing to support her wife. Despite the dewfall that befalls them, he always stood by her side. When Mathilde lost the necklace, he ventured into the street to look for the expensive jewelry in the streets even though he knew the hopes of finding it were low. Monsieur gave her the money meant for purchasing a gown because of the love that he had for his wife. The money was for her dress to attend the party and it happened that Mathilde lost the necklace she had borrowed and wore to the party.