362 



sorption ore performed. A semi-fluid matter, possessing all the cha- 

 racters of albumen, is found closely adhering to the inner coats of 

 the small intestine ; and is more especially abundant around the pa- 

 pillary projection, through which the common duct of the liver opens 

 into the duodenum, and diminishes in quantity as we trace it towards 

 the termination of the ileum. The great intestines are generally 

 distended with a dark green homogeneous fluid, containing no albu- 

 men, and apparently excrementitious. No albumen can be detected 

 in the contents of the stomach. Hence the author infers that an 

 absorption of some nutritious substance, which he brings forward 

 several arguments to show must be derived from the liver, takes 

 place from the intestinal canal in the latter months of gestation. 

 He states that in two instances he detected the presence of a sub- 

 stance, similar to that which he had found in the duodenum, in the 

 hepatic duct itself ; hence he is led to the conclusion that the func- 

 tion of the liver in the foetus is not confined to the separation of ex- 

 crementitious matter from the blopd, but that it supplies materials 

 subservient to nutrition. That the substances existing in the intes- 

 tines of the fcetus are not derived from the mouth, is proved by their 

 being equally found in acephalous children, or where the oesophagus 

 is impervious, as where no such mal-conformation exists. 



A note is subjoined to this paper by Dr. Prout, giving an account 

 of the mode by which he ascertained the chemical character of the 

 substance referred to his examination ; and the. paper is accompanied 

 by drawings of the intestinal tube in the foetus. 



Experiments on the Modulus of Torsion. By Benjamin Bevan, Esq. 

 Communicated by the President. Read December 18, 1828. [Phil. 

 Trans. 1829, p. 127.] 



The object of the author in this paper is to ascertain the modulus 

 of torsion in different species of wood, and also of metals, deduced 

 from experiments on a large scale, which he conceives will furnish 

 many useful data, applicable to practice by the mechanic and en- 

 gineer. Care was taken that the specimens of wood which were the 

 subjects of experiment were sound and dry, and free from any large 

 knots ; and their correct dimensions were ascertained by an improved 

 kind of callipers. 



To every specimen two indexes were attached ; one, a few inches 

 from the end, fixed in the clamp or vice, and the other, at a small di- 

 stance from the attachment of the lever, to which the straining power 

 was applied ; and the length of the bar subjected to torsion was esti- 

 mated by the distance of the points of attachment of the indexes. A 

 pivot was fixed at the supported end of the bar, in lieu of its axis. 



The author gives the following rule for finding the deflection of a 

 prismatic shaft ; namely, that it is equal to the product of the strain- 

 ing power into the square of the radius by which it acts, and into the 

 length of the shaft, divided by the modulus of torsion into the fourth 

 power of the side of the square shaft. IJe then gives a table of the 



