Proof that air is necessary in the development of the embryo. Digital facsimile from Google Books at this link.

Digital facsimile from Google Books at this link.

William Beaumont recognized that the gastric juice contained some other active chemical substance besides hydrochloric acid. Schwann proved this to be pepsin. Digital facsimile from Google Books at this link.

Proof that putrefaction is produced by living bodies. Independently of Cagniard-Latour, Schwann discovered the yeast cell. He is regarded as the founder of the germ theory of putrefaction and fermentation.

Schwann’s three-part preliminary application of Schleiden’s “watch-glass” cell theory to the genesis of animal cells. Schleiden communicated the theory to him verbally. This paper actually pre-dates Schleiden’s first publication (No. 112) but Schwann gives Schleiden full credit for the Uhrglastheorie. English translation with commentary in L.J. Rather, P. Rather, and J.B. Frerichs, Johannes Müller and the nineteenth century origins of tumor cell theory, Canton, Mass., [1986].

Mainly devoted to the investigation of the elementary structure of animal tissues, Schwann’s Untersuchungen had an important bearing on the development of the doctrine of the cell structure of animal tissue. In this work Schwann discarded Schleiden’s Uhrglastheorie and put forward a theory of his own. In the same work he described the neurilemma, the “sheath of Schwann”. Schwann was Professor of Anatomy and Physiology at Liège. English translation (Sydenham Society), 1847. See M. Florkin, Naissance et déviation de la théorie cellulaire dans l’ceuvre de Theodore Schwann. Paris, Hermann, 1960. Digital facsimile of the 1839 edition from Google Books at this link.

Proof of the indispensability of bile to digestion.