Bilbao almonds), rice cakes and "bollos de mantequilla" (butter buns). Bilbao, as other Basque cities, is known for a variety of appetizers and snacks, being prominent among them the "pintxos", which are typically eaten in bars and that consist of small slices of bread on top of which is placed an ingredient or mixture of ingredients, generally of many different types and usually including elements typical of Basque cuisine. Other snacks include "rabas" (fried or battered calamari rings, usually served with lemon slices), Spanish omelette (omelette made with eggs and potatoes, sometimes including onions and peppers), "txampis" (stuffed mushrooms), "triángulos" (Bilbao-style
Active ingredient as salicylic acid in willow bark or arecoline in areca nuts), because the word "ingredient" in many minds connotes a sense of human agency (that is, something that a person combines with other substances), whereas the natural products present in plants were not added by any human agency but rather occurred naturally ("a plant doesn't have ingredients"). In contrast with the active ingredients, the inactive ingredients are usually called excipients in pharmaceutical contexts. The main excipient that serves as a medium for conveying the active ingredient is usually called the vehicle. Petrolatum and mineral oil are common vehicles. The dosage