These rising levels of carbon dioxide are acidifying the oceans. Both preservatives are enhanced by lowering the pH-value (acidifying the ink by adding hydrochloric acid). Carbon dioxide is injected into the canister acidifying the water and dissolving the coral skeletons. Methionine is also known to increase the urinary excretion of quinidine by acidifying the urine. Organic nitrogen sources, such as urea and compost, are less acidifying. Acidifying organic materials include peat or sphagnum peat moss. Example products are herbal preparations, probiotics and vaginal acidifying agents. Usually this is done by acidifying (souring) the milk and adding rennet. He held that all acids contained oxygen and that oxygen was therefore the acidifying principle. These partially dissociate, acidifying the colonic contents (increasing the H concentration in the gut). H+ATPase increases the efflux of H+, thus acidifying the apoplast. The main function of this excretory organ is storing, acidifying and concentrating bile. For example, acid rain can kill trees, and can kill fish by acidifying lakes. The sphagnum wicks moisture to the surface while simultaneously acidifying it. Acidifying the urine has the same effect for weakly basic drugs.