378 Intelligence and Miscellaiieous Articles. 



SUGAU IN HEALTHY BLOOD. 



In the Phil. Mag. for Maj' 1S45, p. 422, are detailed some ex- 

 periments by Dr. R. D. Thomson, which show that when starch 

 has been digested in considerable quantities by animals, it passes 

 into the condition of soluble starch, or dextrine and sugar, and being 

 absorbed in the latter form into the blood, can be detected in that 

 fluid during the period of digestion. The experiments detailed in 

 the paper referred to were made in 1844. Magendie has lately, in 

 a paper communicated to the French Academy {Comptes Rendus, 

 xxiii. p. 1S9), obtained similar results. He found that when a dog 

 was fed on cooked potatoes, the blood contained dextrine and grape- 

 sugar. He observed also, that if starch be mixed with fresh serum, 

 it is so transformed in a few seconds that it cannot be detected by 

 reagents, and in a quarter of an hour sugar makes its appearance. 

 This exactly corresponds with the previous results obtained by Dr. 

 Thomson in 1844, who "was unable to detect any traces of starch 

 in the serum of the blood" (Phil. Mag., May 1845, p. 420), but 

 easily obtained evidence of the presence of sugar in the same blood. 



CHEMICAL ACTION OF LIGHT. 

 To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



The chemical action of light has of late attracted so much atten- 

 tion, that any fact connected with the subject will be received with 

 interest by those engaged in researches on this branch of science, 

 which induces me to ask the favour of your publication of the fol- 

 lowing. 



I have been successful in obtaining well-defined photographic im- 

 pressions on highly sensitive Daguerreotype plates, on which the 

 object, when illuminated by a common dip candle, was impressed in 

 ten minutes ; with the smallest fish-tail burner of coal gas in three 

 minutes ; and by the oil lamp, viz. a solar lamp, in the same time. 

 I included each flame in the picture by which they have recorded 

 their size, and to some extent their illuminating power. 



I at present confine mj'self to the recital of these facts, as I am 

 following up my researches on the subject. I beg to forward the 

 plates for your inspection*. 



I am. Gentlemen, 



234 Regent Street, Your most obedient Servant, 



ApVil 20. W. E. KiLBURN. 



ON THE COMPOUNDS OF CYANOGEN. BY M. AD. WURTZ. 



Formation of Cyanuric Acid. — When a current of dry chlorine gas 

 is passed over fused urea, very energetic reaction occurs ; the urea 

 is decomposed, swelling up and emitting abundant white vapours. 

 The products of this action are cyanuric acid, hydrochlorate of am- 



* These we have received. They appear to us very perfect, and the eflTect 

 highly remarkable. — Ed. 



