It is perfectly true, as Davy surmised, that potassium can combine with more oxygen than is contained in potash, but it is no less true, as he himself proved by his discovery of the so-called _euchlorine_, that chlorine can combine with oxygen. Although he made several attempts to isolate Mr. Chenevix’s hyper-oxygenised muriatic acid, he was not successful at the time, and was evidently disposed to doubt its separate existence. The remaining portion of the paper, although of interest as exemplifying Davy’s power of dealing with the broad issues which his views raise, need not detain us now. He seizes the opportunity, however, to correct his statements with regard to the presumed compound nature of sulphur and phosphorus, and gives details of observations, some of which, as in other of his papers, have been “discovered” by subsequent observers. Thus he states:-- “I have never been able to burn sulphur in oxygen without forming sulphuric acid in small quantities; but in several experiments I have obtained from 92 to 98 parts of sulphurous acid from 100 of oxygen in volume; from which I am inclined to believe that sulphurous acid consists of sulphur dissolved in an equal volume of oxygen.” It was hardly to be expected that views so entirely opposed to the convictions of chemists at the time should pass unchallenged. Berzelius, the countryman of Scheele, warmly defended the doctrine of the French School, and yet another Scotch professor sought to show that Davy was still “vera troublesome.” The controversy, in which Davy himself took little part, occasioned considerable stir at the period, and was even of interest outside philosophical circles. The discussion was not without its uses, inasmuch as it led to fresh discoveries. The noise of it all, however, is now forgotten. Berzelius eventually enjoined his cook to speak no longer of oxymuriatic acid: “Thou must call it _chlorine_, Anna; that is better.” Dr. Murray, with the pertinacity of his race, still clung to the old doctrine, and defended it with no little dialectical subtlety, but he alone was faithful among the faithless. It is true there has been an occasional flutter in the dovecots since these times, and the faith of chemists in the validity of Davy’s teaching has been once or twice assailed, but as yet it has survived all assaults.