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: Effects of uninephrectomy and high protein feeding on lithium - induced chronic renal failure in rats .
### Output Text:
Effects of uninephrectomy and high protein feeding on <span class="chemical">lithium</span> - induced chronic renal failure in rats . 