September 26, 191 2] 



NATURE 



115 



The calculated magnitude for the whole of this 

 I-triod is 50, nnd as the comet sets at about 7 p.m. 

 it is onlv possible, in these latitudes, to see it low- 

 down in the south-west, immediately after sunset. 

 But as the southern declination is decreasing the 

 conditions will become inore favourable ; also as the 

 comet nears the sun it may brighten intrinsically. 

 Consequently, at the beginning of October, it may 

 become visible about an hour after sunset at an 

 altitude of about 10° above the south-western horizon. 



Reported Meteoric Fall in France. — According to 

 a message transmitted by Reuter's Agency a large 

 and brilliant meteorite fell at two o'clock on Friday 

 morning (September 20), in the department of the 

 Aube, Central France. The report states that the 

 meteorite exploded with such great violence as to 

 shake the neighbouring houses and to cause the resi- 

 dents to believe that an earthquake was occurring. 



The G.'vl.actic Distribution of Certain Stellar 

 Types. — In a paper appearing in No. 4600 of the 

 Astronomische Nachrichten, Dr. Hertzsprung pub- 

 lishes some interesting results concerning the distri- 

 bution of certain special types of celestial objects in 

 relation to the galaxy. 



The seven types considered are shown in the follow- 

 ing table, together with the coordinates of the pole 

 of the plane in which each type principally gathers : — 



Coordinates, for igoo, of the pole of the 

 favoured plane 



Type 



■Kj Galactic 



ob ects ^°"=- ''^'- " * 



Helium Stars Oej-Bj, 1402 ... I79'2 +83-0 ... iSa'l 4-270 



Eclipsing variables..'. 150 ._ 2340 +87-3 ... l88-2 4-25-8 



<■ and iK stats gS ... 243-9 4-88T ... 189T 4-26'3 



Type v., Oa o-Oe o 87 ... 3000 4-887 ... 190-7 4-26-9 



Gaseous nebulae ... 130 ... 4-2 4-87-6 ... 192-7 4-28-1 



Type IV., N 22S ... 352-6 4-86-2 ... 194-2 4-27-4 



5 Cephei variables ... 60 ... 3489 4-84-6 ... 195-9 4-26-8 



The data providing these results were taken from 

 vol. Ivi. of the Harvard Annals, and Pickering's value, 

 a= 190°, S= 4-28° (1900), for the position of the galactic 

 pole was used. As will be seen from the results, the 

 type V. stars chiefly lie in a plane nearly coincident 

 with that of the galaxy, while the mean pole for the 

 six other types is practically the same. It should be 

 remarked that the helium stars and those of the fifth 

 type show- a tendency to cluster in various galactic 

 longitudes. Thus 72 per cent, of the helium stars lie 

 within 90° of galactic longitude 248°, and 69 per cent, 

 of the fifth type stars lie within 90° of long. 305°, 

 the two positions 248° and 305° being, respectively, 

 the places of greatest density. 



Radio-active Elements in Celestial Bodies. — 

 Having secured excellent spectrograms of the chromo- 

 sphere during the Spanish eclipse of 1905, Dr. S. A. 

 Mitchell has compared his (unpublished) wave-lengths 

 with those of Exner and Haschek's radium spectrum, 

 and finds himself unable to confirm Prof. Dyson's 

 suggestion that radium may be present in the chromo- 

 sphere. As previously noted in these columns, the 

 chromospheric spectrum is probably adequately ex- 

 plained bv the presence of other elements. Dr. 

 Mitchell finds no sufficient evidence for the presence of 

 radium emanation and uranium in the chromosphere, 

 and deduces that we must wait for better photographs 

 with greater dispersion than those of Nova Gemi- 

 norum (2) obtained by Dr. Giebeler before seriouslv 

 contemplating the presence of these radio-active sub- 

 stances in novEe (Astronomische Nachrichten, 

 No. 4600). 



NO. 2239, VOL. go] 



THE PHYSICAL CHEMISTRY OF THE LOAF. 

 'pHE question of strength in wheaten flour has of 

 ^ late years repeatedly engaged the attention of 

 chemists. Recent researches, more particularly those of 

 Prof. T. B. Wood, have established that strength, or, 

 in other words, the capacity of the Hour to give a bold, 

 well-risen loaf, depends in the main on the influence 

 of the electrolytes naturally present on the gluten. 

 The difficulties of the problem have hitherto prevented 

 a more quantitative study of the electrolytes present 

 in flour, but a recent paper from the Carlsberg Labora- 

 tory, Copenhagen, by Jessen-Hansen, perhaps marks 

 a first step in this direction. Use is made by him of 

 Sorensen's methods of determining small amounts of 

 acidity, either colorimetrically or by determinations of 

 electrical conductivity, to study the degree of aciditv, 

 or, as it is usually termed, the " hydrogen ion con- 

 centration " of a number of doughs made in the 

 usual way. 



In particular, the effect of the addition of different 

 quantities of acid to the dough was e.xamined, and 

 the acidity compared with the result obtained on 

 baking. The conclusion is drawn that there is a 

 certain optimum concentration of hydrogen ions, in 

 presence of w-hich the best results are obtained on 

 baking ; this concentration is rather higher than that 

 of dough prepared from natural flour and distilled 

 water. It differs only slightly according to the 

 quality of the flour, being somew-hat higher for the 

 superior grades and rather lower for the lower kinds ; 

 it also differs slightly in flour milled from different 

 parts of the berry, being highest for the so-called 

 patents. The optimum concentration corresponds 

 approximately to a hydrogen ion concentration of 

 lo~^ normal, pure distilled water being about 10-' 

 normal. It will be obvious that doughs made in this 

 country with the hard alkaline service water must 

 diverge a good deal from this concentration. 



Dr. Jessen-Hansen seeks to explain the effect of 

 the various flour improvers which have been brought 

 forward during the last year or so, as due to their 

 increasing the hydrogen ion concentration and not to 

 any subtle working of the improver, as the patentee 

 would sometimes have us believe. Nothing is said, 

 however, to indicate in what way the optimum acidity 

 may be supposed to condition the subtle changes in 

 the gluten which produce a good loaf. It is perhaps 

 significant that the acidity also corresponds to the 

 optimum aciditv for protein coagulation. 



E. F. A. 



AGRICULTURE IN INDIA.'^ 



IN his report on the condition of agriculture in 

 India, Mr. Coventr\' is able to state that the 

 progress recorded in earlier reports has been well 

 maintained, and the beneficent and productive 

 character of the Department's undertakings made 

 much more apparent. Sustained efforts are being 

 made in the cotton tracts to improve the quality and 

 increase the quantity of the staple. In Madras, the 

 improvements have taken two lines — the separation 

 and selection of the best indigenous variety and the 

 introduction of the exotic Cambodia. Similar 

 improvements are also noted in the Central Provinces 

 and Bombay. The well-known w-ork of Mr. and 

 Mrs. Howard on the improvement of Indian wheats 

 is being carried on, and has entered a new phase by 

 the establishment of seed farms where the new varie- 

 ties can be grown on the large scale for distribution 



1 Report on the ProEress of Agriculture in India. (Calcutta, 1912.) 

 ^(emoirs of the Dei)artnient of Agriculture in India. (Pusa.) 

 T/i( AgricnlturalfoHrtialof India. (Pusa.) 



