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: The patient was successfully treated with intravenous pamidronate on his first admission and with hydrocortisone on the second .
### Output Text:
The patient was successfully treated with intravenous <span class="chemical">pamidronate</span> on his first admission and with <span class="chemical">hydrocortisone</span> on the second . 