The pH scale is a scale that is used to represent the level of acidity in a solution. A solution with a pH of 7 is neutral, while a solution with a pH below 7 is an acid, and a solution with a pH above 7 is a base. An acid dissociates, or breaks apart, and donates protons, or hydrogen ions, in an aqueous solution, while a base donates hydroxide ions in a solution. Water, for example, is neutral with a pH of 7. When acids are added, they release more hydrogen ions into the solution, and this causes the pH of the solution to drop.
Two days later, EA CEO John Riccitiello stated that Spore would be released sometime before the holidays. On February 12, 2008, Electronic Arts announced in an official press release that the official release date would be September 5, 2008 for Europe and September 7, 2008 for North America.
The work was so urgent that they came in to begin the experiment on the weekend, and on Saturday 25 May, Florey's team tested penicillin on eight mice injected with a lethal dose of streptococci bacteria. Four of the mice were treated with penicillin, while four were used as controls.