326 Dr. Winn on the Production of Heat, Sfc. 



In the following table the results of the preceding analyses 

 are collected, so as to exhibit the comparative value of each 

 specimen. The first column gives the amount of azotized 

 principles contained in each, and the second column repre- 

 sents their equivalent values in the nutritive scale. 



1. Naumburg bread . . . . 16*49 . . 100*00 



2. Dresden bread 14*30 . . 115*31 



3. Berlin bread 14*21 . . 116*04; 



4. Canada flour 13*81 . . 117*23 



5. Essex flour 13*59 . . 121*33 



6. Glasgow unfermented bread . 13*39 • • 123*15 



7. Lothian flour 12*30 . . 1 34*06 



8. United States' flour . . . . 11*37 . . 145*03 



Ditto, by mechanical analysis 10*99 . . 150*00 



This table shows that the German and Canada flour con- 

 tain most nutritive matter ; the Essex flour being only a slight 

 degree lower in the scale. It must be borne in mind, how- 

 ever, that this result may not be in consonance with the 

 opinion of the baker in reference to the capacity of the flour 

 for making good bread, because it takes in another element, 

 the albumen, which is omitted in the baker's estimate. It is 

 therefore quite possible that the specimen holding the lowest 

 position in the table may answer the purpose of the baker in 

 an equal or superior manner to those placed above it ; but 

 the method of determining the comparative value of flour by 

 the estimation of the azote may furnish us at once with data 

 of utility both in commerce and ceconomy*. 



XXXIX. On the Production of Heat by the Contraction of 

 Elastic Tissue, in reference to a former communication. By 

 J. M. Winn, M.D. 



To the Editors of the Philosophical Magazine and Journal, 



Gentlemen, 

 N Dr. Gregory's translation of Liebig's ' Animal Chemis- 

 try,' I find at page 31 the following remark : — " The obser- 

 vation has been made that heat is produced by the contrac- 

 tion of muscles, just as in a piece of caoutchouc, which, when 

 rapidly drawn out, forcibly contracts again with disengage- 

 ment of heat." With the exception of an essay in the Lancet 



* The result of Sir H. Davy in reference to the quantity of gluten in 

 British flour, is sometimes nearly the double of the numbers in the table. 

 This may perhaps be ascribed to his mode of drying the gluten. 



1 



