CHEMICAL SCIENCE. 191 



REMARKS ON THE ALIMENTATION OF COFFEE. 



THE preceding paper having been submitted to the French Acade- 

 my, M. Magendie presented a communication on the same subject. 

 " It is true," says he, " that alimentary substances which contain lit- 

 tle or no nitrogen are not nutritive, but to conclude, as is often done, 

 that the proportion of nitrogen contained in an element gives exactly 

 its nutritive power, is to greatly exceed the truth deduced from the 

 experiments which have been made on this point of physiology. 

 Many highly nitrogenous substances are not nutritious. Animals 

 die of inanition on eating considerable quantities of gelatine, albumen, 

 &c. They perish in the same space of time as if they had been fed 

 on water alone. Fibrine itself, the almost sole base of muscular 

 flesh, is not nutritive before having undergone its mysterious con- 

 version into muscle. Dogs which eat at pleasure several kilogrammes 

 of fibrine of the blood per day, and which digests perfectly, die, 

 nevertheless, with all the symptoms of inanition, after a month of this 

 very nitrogenous regimen. This same fibrine, cooked in excellent 

 meat broth, which supplied the savory and saline principles of flesh, 

 given as exclusive nourishment to dogs, was eaten with avidity by 

 them, but did not nourish them ; while dogs fed exclusively with glu- 

 ten were well nourished, and for a long time. Raw flesh nourishes 

 perfectly, and in very small quantity. Dried flesh nourishes much less. 

 I have proved by experiments, that, to nourish a carnivorous animal, it 

 is necessary to give in dry meat the same weight as of raw meat. 

 Here the disproportion of the nitrogen in the two aliments is enormous, 

 since raw meat in drying often loses nine tenths of its weight, retain- 

 ing its nitrogen ; therefore in these experiments nine or ten times as 

 much nitrogen was required for obtaining the same nutritive result. 

 Why this enormous difference between the nutritive properties of the 

 same substance? Does the heat most frequently employed in the desic- 

 cation, as is the case with ferments, destroy certain properties of mus- 

 cular flesh? In conclusion, I may add that every thing connected with 

 the theory of nutrition is still concealed by an impenetrable veil. We 

 know little or nothing concerning this important and fundamental phe- 

 nomenon. We are beginning to comprehend the various acts of di- 

 gestion, but all that happens after the formation and absorption of the 

 chyle, all that passes in the blood and in the connection with the or- 

 ganic tissues and fluids, is still enveloped in the most complete obscu- 

 rity." Statique Chimique des Animaux. 



INFLUENCE OF SALT ON VEGETATION. 



DR. VOLCKER presented a paper to the British Association contain- 

 ing the result of a series of experiments on the influence of solutions 

 of salt on various plants, as cabbages, beans, onions, lentils, chick- 

 weed, groundsel, the thistle, radishes, and some grasses. None of 

 these plants were affected during one month by solutions containing 

 24 grains of chloride of sodium to the pint of water, with the excep- 

 tion of Anthoxanthum odoratum, which was killed. Cabbages, rad- 



