672 tJRANSACiTIONS OV SECTION H. 



cold alcohol (95 per cent, by weight) that the resultiug strength is about 80 pel' 

 cent. The a-amylodextriu is removed by filtration and the alcohol from the 

 filtrate by distillation. The maltose syrup may be seeded with a small quantity 

 of pure maltose and a little alcohol added. Usually in the course of a few hours 

 a solid magma of practically pure maltose is obtained. This may be further puri- 

 fied by triturating the sugar with strong alcohol, filtering, dissolving in a very 

 small quantity of water, and pouring into boiling 95 per cent, alcohol, again filtering, 

 and crystallising the maltose from the filtrate. Prepared under these conditions, 

 maltose separated in well-defined and relatively large plates mixed with irregular 

 crystalline masses. 



"When analysed it had a specific rotatory power (a)D3D:!abs. = 137°'l, and a 

 reducing power, determined under the conditions described by Brown and Millar, 

 102-9. The osazone, which melted at 195°, consisted entirely of characteristic 

 broad prisms resembling ribbons in the microscopic field. The stellate aggregates 

 of crystals, which are always present in the osazone from maltose prepared by tiie 

 action of malt diastase on starch, were entirely absent. On acetylation the 

 characteristic octacetyl maltose was obtained. 



Since the microscopic appearance of the maltose suggested the possibility of a 

 mixture, a large quantity of the sugar was collected and carefully fractionated by 

 dissolving in v/ater and collecting successive crops of crystals. The fractions had 

 specibc rotatory powers of (a)i> = 137'5 to 138'4 abs. and reducing powers of 

 101"0 to 103*0 (calculated from Brown and Millar's Tables). The residential 

 mother liquor also had the constants (a)D=3'y3 abs. + 137"4 and R = 994. 

 Maltose of this degree of purity separates with remarkable ease from strong 

 aqueous solutions. 



It will be noted that the reducing powers are all slightly higher than the 

 values recorded by Brown and Millar. We believe this to be due to the great 

 difficulty of preparing pure maltose by the action of malt diastase on starch. 



Joint Discussion with Sections A and 6 on Gaseous Explosions. 



MOMDAT, SEPTEMBER 1. 

 The following Papers and Report were read : — 

 1. The Inactive Gases. By Sir William Ramsav, K.C.B., F.H.S. 



2. Lithium in Radio-active Minerals. 

 By Professor W. N. Hartley, D.Sc, F.R.S. 



The question as to whether lithium is or is not a widely occurring element, 

 and whether it is found associated with any other element, more particularly with 

 copper than with the alkalis or the alkalme earths, arises from the assumed 

 transmutation of copper contained in solutions, into lithium, neon, and possibly 

 other substances. 



It has been stated by Sir William Ramsay : — ' 



* As sodium and potassium are much more widely distributed than lithium, it 

 is more likely that they are the chief products from copper, and that some modi- 

 fying circumstance has determined the formation of a trace of lithium. . . . 

 Lithium was mentioned because it is an unlikely constituent of dust, glass, 

 copper, &c., which were tested specially to prore its absence.' 



' Nature, March 5, 1908 p. 412. 



