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: Neither the type of induction agent ( Althesin or Thiopentone ) nor the salt preparation of suxamethonium used ( chloride or bromide ) , affected the incidence of scoline pain .
### Output Text:
Neither the type of induction agent ( <span class="chemical">Althesin</span> or <span class="chemical">Thiopentone</span> ) nor the salt preparation of <span class="chemical">suxamethonium</span> used ( <span class="chemical">chloride</span> or <span class="chemical">bromide</span> ) , affected the incidence of <span class="chemical">scoline</span> pain . 