Bennett visited Paris and Germany, and learned there of the beneficial effects of cod liver oil. His book drew the attention of English medical men to the value of the oil.

Bennett confirmed and extended the observations and experiments of Gruby concerning the mycodermatous vegetations found in the crusts of the disease called Tinea favosa, or Zorigo lupinosa of Bateman; he announced the occasional existence of, and described, a plant found growing on the lining membrane or cheesy matter of tubercular cavities in the lungs of man. This was the first description of aspergillus (a pathogenic fungus) growing in the lung tissue of humans.

Digital facsimile of the separate offprint (copy inscribed by Bennett to Bischoff) from the Hathi Trust at this link.

First definite description of leukemia as a blood disorder; a case under the care of Sir R. Christison but reported by Bennett. On p. 400 of the same journal is a report of a case by D. Craigie, referring to a patient seen in 1841 but not recognized as leukemia until Craigie heard of Bennett’s case in the same hospital. Bennett published a monograph on leucocythemia in 1852, in which he included the first illustrations of the microscopic appearance of the blood in leukemia.

Bennett provided a scientific explanation for then current mass hysteria or group hypnosis in Edinburgh. Digital facsimile from Google Books at this link.