In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Partial lesions were made with kainic acid in the interpeduncular nucleus of the ventral midbrain of the rat .
### Output Text:
Partial lesions were made with <span class="chemical">kainic acid</span> in the interpeduncular nucleus of the ventral midbrain of the rat . 