336 ANNUAL OF SCIENTIFIC DISCOVERY. 



per cent. It is well known that millers and bakers consider the excellence 

 of flour to be in proportion to the amount of starch. Contrary to the opinion 

 of Liebig, and of most chemical physiologists, the authors maintained that 

 the bakers' standard is the correct one ; or at any rate that the least nitro- 

 genizcd bread contains an ample sufficiency of nitrogen, and that the great 

 demand for food is for its respiratory or carboniferous constituents. From 

 a large number of analyses of flour, in which the gluten was separated 

 mechanically, it appeared that, both in Europe and America, in proceed- 

 ing from the north to the south, the proportion of gluten gradually increased, 

 and, consequently, according to the authors' criterion of high maturation, 

 the most matured crops were grown in the coldest latitudes. 



LACTIC ACID IN VEGETABLES. 



Professor Wittstein, a German Naturalist, has announced the discovery 

 of Lactic Acid, heretofore considered of exclusive animal origin, in vegeta- 

 bles, especially in the peduncles of solanum dulcam ara, and in the liquid 

 which dropped from freshly cut vine branches. It would seem the further 

 researches are carried, the fewer distinctions remain between vegetable and 

 animal substances. Journal of Medicine. 



ORIGIN OF UREA IN THE ANIMAL ECONOMY. 



Dumas has announced with much enthusiasm the confirmation of his 

 views already old respecting the origin of t urea in the animal economy, 

 namely, that the urea proceeds from the albuminoid substances destroyed 

 in the blood by an oxydating process. This is now established by M. Bc- 

 champ, Professor at the School of Pharmacy of Strasbourg, who has suc- 

 ceeded in changing albuminc fibrine and gluten into urea by a slow com- 

 bination proceeded by means of a solution of permanganate of potash at 

 the temperature of about eighty degrees C. The following is the pro- 

 cess : 



Ten grams of aluminum are dissolved in 300 grams of water ; and to 

 this by degrees seventy-five grams of permanganate of potash are added. 

 The reduction, which is at first very active, soon ceases. It is then heated 

 to forty degrees C. in a water bath, and from time to time saturated with 

 sulphuric acid, yet so as to leave it still a little alkaline. When the discol- 

 oration is completed, it is filtered, and exactly saturated with dilute sul- 

 phuric acid. The solution, now perfectly limpid, is evaporated inaw:i:ur 

 bath ; and when reduced to a small volume, an excess of concentrated 

 alcohol is added ; it deposits some sulphate of potash and sulphate of am- 

 monia. The alcoholic solution is evaporated in its turn to the consist- 

 ence of honey and treated with hot absolute alcohol, which dissolves the 

 urea. 



"Whilst M. Bcchamp was bringing out this transformation, a physiologist, 

 M. Picard, made, also at Strasbourg, some observations bearing on the sub- 

 ject, having reference to the presence .of urea in the blood and its diffusion 

 through the system. 



It is known that according to MM. Dumas and Provost, urea shows 



