908 Transactions of the A^ierican Institvts. 



March 6, 1868. 

 Prof. S. D. Tillman in the chair. 

 The following articles frcm the pen of the Chairman were first 

 read: 



DIETETIC CONDIMENT. 



For the prevention and cure of certain diseases, traceable to 

 dietetic errors, Dr. Lankester adds to common table salt (chloride 

 of sodium) small proportions of phosphate of lime, chloride of 

 potassium, sulphates of potash and soda, and still smaller, of mag- 

 nesian and iron salts. The object of the inventor will be understood 

 by stating that consumption, scrofula, and softening of the bones 

 are supposed to result from a deficiency of phosphate of lime and 

 other salts; scurvy, from the absence of potash; and nervous dis- 

 orders from a want of iron in the blood. This plan of guarding 

 against human ills generally by a single condiment, reminds one 

 of the early attempts to drive ofi" disease, before a proper diagnosis, 

 by administering a compound of numerous medicinal roots, in the 

 hope that at least one of them would meet the case and prove an 

 antidote; while all the remaining ingredients, finding their services 

 were not required, would reserve their force and quietly withdraw 

 from the contest, or at least produce no pernicious eft'ect upon the 

 patient. 



INFLUENCE OF COLORED LIGHT ON PLANTS. 



Recent experiments by L. Cailletet confirm those made many 

 years ago by Morren, of France, with regard to the influence of 

 the luminous rays in vegetable growth. The former advances a 

 step further by including the red, as well as the yellow ray, among 

 those most favorable in promoting the decomposition of carbonic 

 acid gas by plants. All the rays more refrangible than the yellow 

 are powerless in this respect. Under the influence of green light, 

 not only does no decomposition take place, but new quantities of 

 carbonic acid are formed, the exhalation of the gas by the fresh 

 leaf being nearly as much under this condition as when placed in 

 the dark. Light passed through a solution of iodine in bisuli)hide 

 of carbon, prevents decomposition of the acid, and the appropria- 

 tion of carbon by the plant, but does not seem to increase the 

 quantity of acid, which might be inferred from the fact that the 

 violet is the most refrangible of the colored rays. Many experi- 

 ments have been made in this country which give the same general 

 results as those of Morren and of Dr. Daubeny, of England, but 

 differ somewhat from those of Cailletet. 



