462 Scientific Intelliyence, §'c. 



Dr. Williams said, he believed the elasticity of the heart was 

 sufficient to account for the phenomenon of its dilatation. 



A paper " On the Polarization of Light observed in the Crystal- 

 line Lens, by Sir David Brewster," was read by the President ; as 

 was also a letter from the same gentleman on the subject of cataract, 

 which, if resisted in its early stages, the author believed might be 

 overcome. This disease, which generally manifested itself between 

 the ages of forty and sixty, when persons begin to require spectacles, 

 Sir David gave a receipe for detecting, which he had done in his 

 own case; and though, perhaps, induced by an impaired state of 

 health, yet, by attention to diet and regimen, and taking care not to 

 study by night, he found in about eight months he was cured. If 

 the affection had not been checked in time, he entertained no doubt 

 it would have ended in cataract. 



The last paper read was On Absorption, by Dr. Carson, of 

 Liverpool. 



Friday, 2Qth August. — Mr. Adams stated the appearances he had 

 observed in Chronic Rheumatism, viz., as in the arm, enlargement 

 of the glenoid cavity and head of the humerus, and loss of the 

 tendon of the biceps. He described several other morbid appearances, 

 and shewed specimens. 



Mr. Hetling read a paper " On a New Instrument for the removal 

 of the Ligature of Arteries at pleasure." 



Mr. Gordon exhibited some Anatomical Models. 

 The last paper read, was " On the Chemistry of the Digestive 

 Organs," by Robert D. Thomson, M. D. The author began by 

 drawing attention to the necessity of admitting chemical action as 

 an important agent in digestion, because, inasmuch as every change 

 in the position of the ultimate particles of matter is a chemical 

 or electrical change, so the conversion of food into chyme and its 

 assimilation must fall under this head. Dr. Thomson divided the 

 consideration of the subject into — I. Chemical state of the stomach, 

 first, in health ; and, secondly, in disease. II. Chemical state of the 

 mouth and cesophagus, first, in health ; and, secondly, in disease. 

 I. First, He remarked, that our most eminent physiologists had 

 completely overlooked the experiments of Dr. Prout and others, 

 which establish the fact, that in health the stomach contains a quan- 

 tity of free muriatic acid. He referred to the recent experiments of 

 Braconnot, who had found a great quantity of this acid in the 

 stomach, and who had determined by very satisfactory experiments 

 that no lactic acid was present. The author detailed an experiment, 

 in which he had succeeded in converting muscular fibre into a substance 

 exactly resembling chyme, by digesting it in dilute muriatic acid, on 

 the sand-bath, during ten hours, taking care to keep the mixture as 

 nearly as possible at a temperature equal to that of the human body. 

 He, therefore, drew the conclusions : — first, that the stomach, in a 

 state of health, when excited by stimulants, contains a quantity of free 

 muriatic acid; and, second, that dilute muriatic acid is capable of pro- 

 ducing by digestion with animal matter, at the temperature of the 

 human body, a substance similar to chyme in its physical properties. 

 From which it may be inferred, that free m.uriatic acid is an important 



