RECENT ADVANCES IN SCIENCE 549 



upon carbonic acid must be regarded as the mutual reduction 

 of two peroxides according to the equation 



H 2 2 + ^ J I /CO I = H 2 + 2 + HCOOK 



The best results for the above reaction are obtained by 

 the action of a 10 per cent, solution of hydrogen peroxide 

 upon a saturated solution of potassium bicarbonate. It has 

 also been found that a formate is similarly produced around 

 the anode during the electrolysis of a carbonate or bicarbonate 

 since the peroxidic anion is then in contact with hydroxyl ions. 



The constitution of carnosine, one of the chief bases con- 

 tained in extract of meat, has now been finally established 

 (Baumann and Ingvaldsen, /. Biol. Chem. 191 8, 35, 263) by 

 removing the amino radicle of this substance by means of 

 barium nitrite and sulphuric acid and hydrolysing the result- 

 ing product with 70 per cent, sulphuric acid ; a theoretical 

 yield of histidine was obtained, thus showing that carnosine is 

 /3-alanylhistidine I., and not histidyl /3-alanine II. 



NH-CH 



I >C . CH 2 . CH(NHCOCH 2 CH 2 NH 2 )COOH 



CH = N x 



NH-CH. 



>C . CH,CH(NH 2 ) . CONH . CH o CH 2 C00H 



CH = N x 



11. 



The constitution I. has been further confirmed by the synthesis 

 from histidine and /3-iodopropionyl chloride and treatment of 

 the resulting compound with ammonia ; attempts to synthesise 

 the other compound (II.) have so far been unsuccessful. 



GEOLOGY. By G. W. Tyrrell, A.R.C.Sc, F.G.S., F.R.S.E., University, 

 Glasgow. 



Petrology. — F. F. Grout discusses the possibility of convection 

 as a means of producing heterogeneity in igneous magmas 

 (Journ. Geol. 1918, 26, 481-99). In starting a convection 

 current he believes that the increase in aggregate density of a 

 portion of the magma, due to the growth of crystals, is more 

 effective than the separation of gas or of non-consolute liquid 

 36 



