lo May, 1909.] X on-Gcrniiiiaiion of Certain Sorts of Barley. 



!9S 



•those obtained at room-temperature. A later, series when the temperature 

 a\eraged 20° C, gave a much lower percentage germination. 



The two last experiments were carried out at room- temperature (25- 

 30" C), so that the treatment with sulphuric acid only favours germina- 

 tion when the comparisons are with untreated grain germinated at low 

 temperatures. 



After the barley has been in the concentrated sulphuric acid for five 

 minutes the whole is completely black and apparently the .seed quite spoilt, 

 but after washing and neutralization with ammonia or lime water the grain 

 is seen to be sound and of good colour. The latter, however, slowh- 

 alters again, the resulting malt having a rather bad yellowish or brown 

 colour. In addition the cost of the treatment would be heavy on a large 

 scale,* and the fact that sulphuric acid is often contaminated with axsenic 

 Avould bring a risk into malting Avhich past experience has proved to be 

 a real one. 



Mr. Barrett informs me that germination at a high temperature tends 

 to bring so> much of the phosphates and proteids of the seed into a soluble 

 form as to result in the production of a poor class of malt unsuited for 

 brewing a good clear lieer, and especially apt to become contaminated with 

 detrimental micro-organisms. 



To strip off the paleae on a large scale is not possible to do at any 

 reasonable cost without destroying or damaging the germ, and exposing 

 the endosperm. Whether soaking the seeds in w^arm water under high 

 pressure, or in w^ater saturated with compressed air or oxvgen. would be 

 effective is doubtful, and special apparatus would be necessary to carry 

 out such experiments o-n a reasonablv large scale. There are, however, 

 other ways in which germination can be stimulated in seeds. For instance 

 Xagaoka found that the germination of rice was favoured by the action 

 of a dilute solution of manganese sulphate, and Bertrand found the same 

 to be the case with oats.t Micheels and Deheint have found that 

 colloidal .solutions of various metals (tin, platinum, manganese), prepared 

 by passing a high voltage current l)etween plates of the metal suspended in 

 water, exercise a stimulating action on the germination of peas, wheat, 

 barley, and other .seeds. They also state that, in the pre.sence of metallic 

 salts, the passage of a weak continuous electric current through the water 

 on which the germination tray.s are resting, favours germination if the 



*The sulphuric acid could be used repeatedly if the jrrain was dry, but even then 

 the cost of treatment might exceed is. per sack for the acid, while the manipulation 

 on a large scale would be somewhat difficult and dangerous. 



tNagaoka, Bull. College of Agriculture, Tokyo, 1904; Bertr;ind, Tompt. Rendus, 

 t, CXLI., 1Q05, p. 1255. 



iAcad. Roy de Belgicpie, Bull. CI. des Si., iqos, Xo. 7; iqo6. No. 5; 1907, No. 2, 

 1907, No. 12. 



