Here is the Morning Post’s account of Ernst’s attack of illness on stage at the Moscheles concert in London in June 1844. It is important because it helps to identify the condition from which Ernst suffered. In chapter 19 of HWE, I speculated that Ernst suffered from acute intermittent porphyria (AIP), one of whose symptoms, during attacks, is an irregular and racing heart-beat, although I said there was no evidence to support the idea that Ernst suffered from this symptom. [HWE:221] The passage below, however, indicates beyond doubt that, during attacks, Ernst did suffer from serious heart problems, thereby supporting the AIP hypothesis:
In the first part of the concert, M.Ernst was announced to play on the violin an allegro, adagio and rondo valse; and he had completed two movements when he faltered and grew pale, indicating that he was seized with some sudden indisposition; he staggered a little to one side, and at length abruptly left the orchestra. It was presently announced that he was taken seriously ill and the attendance of any medical gentlemen who might be present was requested. Two or three obliged at the summons, and it was afterwards learned that he was labouring under a disease of the heart, which during the excitement of playing had manifested unusually alarming symptoms, but by timely restoratives they had abated. [When he returned] he looked deplorably ill, and every one regretted that his desire to fulfil his promises to the public should have urged him to so imprudent a measure as a reappearance. However, he got through his task magnificently, with a depth of feeling he never before exceeded. The circumstance of his illness threw a damp over the concert, which was only partially removed during the remainder of the performances. We believe something of the same kind happened to him last year, when he was playing for a charity concert; attributable to the same cause – that of strong nervous excitement and overwrought sensibility.
Morning Post, 6/7/1844, p.6