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: Calcium chloride depressed or almost completely abolished the vocalization and fighting due to carbachol and eserine .
### Output Text:
<span class="chemical">Calcium chloride</span> depressed or almost completely abolished the vocalization and fighting due to <span class="chemical">carbachol</span> and <span class="chemical">eserine</span> . 