38o SCIENCE PROGRESS 



Strength in Wheaten Flour " by Martin (/. Soc. Chem. Ind., 

 1920, 39, 247 T). 



Vitaniines. — A new method of investigating vitamines 

 quantitatively has been devised by Williams (/. Biol. Chem., 

 1920, 42, 259). A certain quantity of the solution to be tested 

 is mixed with 100 c.c. of a standard culture solution containing 

 asparagine and ammonium sulphate, and after making up to 

 no c.c. the whole is sterilised. One c.c. of a freshly prepared 

 suspension of yeast containing 0-3 gm. of yeast per litre is 

 added, and the mixture is incubated for eighteen hours. 

 Further growth is stopped by the addition of formaldehyde, 

 and after removal of any wild yeast on the surface, the yeast 

 proper is filtered off on a Gooch crucible, washed with water and 

 alcohol, dried for two hours at 103° and weighed. The weight 

 produced minus the amount produced in a control is propor- 

 tional to the amount of vitamine present. The number of milli- 

 grams of yeast produced by the addition of i gm. of material 

 is known as the " Vitamine Number " of that substance. A 

 steady stream of papers deahng with vitamines and their 

 occurrence in plants, etc., continues to pour forth, especially 

 from the American Journal of Biological Chetnistry, as well as 

 our own Biochemical Journal, and to these two sources readers are 

 referred for particulars ; many of the results obtained by the 

 various workers are contradictory, but the elusive nature of 

 these substances is sufficient to account for this unsatisfactory 

 state of affairs. 



The question of whether vitamines are necessary for the 

 development of plants is answered in the negative by Lumiere 

 {Compt. rend., 1920, 171, 271), from the observation that the 

 addition of brewer's yeast heated to 135°, which no longer cured 

 polyneuritis in pigeons, to a poor culture solution considerably 

 improves the growth of fungi on such a solution. 



BOTANY. By E. J. Salisbury, D.Sc, F.L.S., University College, London. 



Taxonomy. — Spencer le More, in the Journal of Botany, de- 

 scribes several new genera under the names of Homaliopsis 

 (Flacourtiacese), Vaughania (Leguminosae), Umbellulanthus 

 (Erythroxylaceae), and Monocephalium (Icacinaceae) ; also 

 new species of Noronhea, Lasiosiphon, Hemigraphis, Pseuder- 

 anthemum, Justicia, Halemacanthus, Nectar op etalum, Stachy- 

 anthus, Pyrenacantha, Strombosia, and Strombosiopsis. Mr. 

 Ridley in the same Journal describes a new species of Entada, 

 and T. and T. A. Stephenson give a useful account of the 

 British species of Epipactis. 



The Naturalist (September-November) contains a key to 

 the genera of British Agaricaceae, compiled by Dr. Wager. A 



