;90 



NA TURE 



[August 20, 1891 



•nine advance's are 1592, 1630, 1675, 1712, 1735, 1767, 1814, 

 1835, 1875 (?). The following are some of Richter's con- 

 clusions :— Glacier advances recur in periods varying between 

 twenty and forty-five years ; on the average of three centuries, 

 thirty-five years. The advances are not all of equal intensity, 

 nor alike in their progress. Nor is the intensity in a given 

 advance- period the same in all glaciers. In the case of some 

 glaciers, a period is occasionally skipped, the advance or retire- 

 ment being very weak, so that the thirty-five years period gives 

 place to one of seventy years. The glacier variations corre- 

 spond, in general, with Briickner's climate variations. The 

 glacier advance generally begins a few years after the moist and 

 cool period has set in. There is no good reason to suppose 

 that, in historic time, before the sixteenth century, the Alpine 

 glaciers were smaller than now, or that variations occurred of 

 <lifferent order and period from those of the last 300 years. 

 About 1880, the earth was passing through a moist and cold 

 period, which should have resulted in a general advance ; but 

 the advance has been but slight hitherto, and, in th2 Eastern 

 Alps, mostly absent. The cause of this is not at present clear, 

 ■but the mild nature of this last cold period may have something 

 to do with it. 



The bacillus of tuberculosis, it is known, is often to be found 

 in places lived in by consumptives. Herr Prausnitz has lately 

 collected the dust in various compartments of trains which often 

 convey patients from Bsrlin to Meran, and inoculated a number 

 of guinea-pigs with it. Two, out of five compartments so 

 examined, were found to contain the bacillus ; the dust of one 

 ■rendered three out of four guinea-pigs tuberculous ; that of the 

 other, two. The animals were killed after ten to twelve weeks, 

 but in no case was the disease very advanced ; the author 

 supposes the number of bacilli to have been but small. Tlie 

 facts, however, seem to point to the necessity of disinfection of 

 such railway carriages, especially the carpets or mats. 



To the usual well-known ways of stimulating muscles to con- 

 raction, viz. electrical, thermal, mechanical, and chemical, M. 

 D'Arsonval has recently added that by means of light. He 

 could not, indeed, get any contraction in a fresh frog-muscle, 

 when he suddenly threw bright light on it in a dark chamber ; 

 but having first in darkness stimulated a muscle with induction 

 currents too weak to give a visible effect, and then suddenly 

 •illuminated the muscle with an arc light, the muscle showed 

 slight tremulation. Not thinking this conclusive, however, M. 

 'D'Arsonval attached a muscle to the middle of a piece of skin 

 ■stretched on a funnel, and connected the tube of the funnel by 

 means of a piece of india-rubber tube with the ear. The muscle 

 being now subjected to intense intermittent light, he heard a 

 tone corresponding to the period of illumination, and this 

 ceased when the muscle was killed with heat. Arc light was 

 ■used, which was concentrated by a lens and passed through an 

 alum-solution to stop the heat rays. 



For nearly two years there has been at work in Denver, Colo., 

 an automatic refrigerator system, which seems to be thoroughly 

 successful. Ammoniacal liquor in the proportion of 29 parts 

 -pure ammonia to 71 parts water, is forced through a main to the 

 point where refrigeration is desired ; a sudden increase of space is 

 afforded there for quick vaporization, and after absorption by 

 water, the liquid returns by suction to the central station. There 

 are two miles of mains having connection with twenty-nine 

 boxes, each containing a grill near the top to which the liquor is 

 admitted. The space formerly devoted to ice is a clear gain ; 

 and the temperature, instead of being a varying quantity, 

 dependent on the arrival of the ice man, and never below 40° F. , 

 can be reduced to any degree above 25° F. in a few minutes, 

 And kept within 2° of the same. The air is dry, sweet, and 

 NO. I 138, VOL. 44] 



clean ; the moisture collects on the grill as frost. In one experi- 

 ment a piece of meat was kept six months and then cooked and 

 eaten, and it seemed no way different from fresh meat. 



The French Societe de I'Encouragement lately offered a prize 

 of 1000 francs for conservation of potatoes and other vegetables. 

 Four of the hve applicants used some isolating substance (wood- 

 ash, sawdust, rye-straw with sand). M. Schribaux, who gained 

 the prize, puts potatoes for ten hours in a i^ per cent, solution 

 of commercial sulphuric acid to kill the buds (a 2 per cent, solu- 

 tion for thick skins). The potatoes are taken out and thoroughly 

 dried, and they will keep without alteration more than a year. 

 The same solution serves for repeated immersions, the con- 

 centration remaining constant. The process is not applicable to 

 onions. Another prize by the same Society (3000 francs) is 

 awarded to M. Candlot for a memoir treating of the action of 

 sea-water on cements. He shows that the sulphate of lime 

 resulting from decomposition of sulphate of magnesia by lime- 

 salts of the cement combines with aluminate of lime to give a 

 double crystalline salt containing half its weight of water. The 

 crystallization of a salt so greatly hydrated involves considerable 

 swelling, and this accounts for the disaggregation of cements in 

 marine work. M. Candlot has observed the curious fact that 

 over-baked lime, which takes several days to extinguish in 

 water, is extinguished in a few minutes in a 3 per cent, solution 

 of chloride of calcium. This is thought to have important 

 .practical bearings. 



M. Rasp.'vil has lately called attention, in the Zoological 

 Society of France, to the serious diminution of birds in that 

 country through destruction of their nests. Some insectivorous 

 species are becoming very rare, while the ravages of parasites on 

 useful plants are extending. Boys, of course, do a great deal of 

 the mischief; and of the various animals which attack nests 

 (the squirrel, the hedgehog, the dormouse, the magpie, &c. ) 

 M.- Raspail regards the cat as the worst offender. On a recently - 

 wooded property of about 7 acres he observed last year as 

 follows : — Out of 37 nests, carefully watched, only 8 succeeded ; 

 29 were destroyed, 14 of these by the cat, though effort had 

 been made to ward off this insatiable marauder. On a large 

 property in the centre of a village the owner had about 80 cats 

 annually caught in traps. The place having lately changed 

 hands, the gardeners estimate that more than 100 nests were 

 destroyed last year, three-fourths of these by cats. M. Raspail 

 advocates a rigorous application of the law for protection of 

 insectivorous species, the disqualification of the cat as a domestic 

 animal, and the giving of prizes to foresters and others for de- 

 struction of all animals which prey on eggs and young in the 

 nest. 



Tobacco fermentation, a very essential process, is brought 

 about by firmly packing ripe tobacco in large quantities. It had 

 been generally supposed that the fermentation is of purely 

 chemical nature, but Herr Suchsland, of the German Botanical 

 Society, finds that a fungus is concerned in it. In all the 

 tobaccos he examined, he found large quantities of fungi, though 

 of only two or three species. Bacteriacese were predominant, 

 but Coccacese also occurred. When they were taken and in- 

 creased by pure cultivation, and added to other kinds of 

 tobacco, they produced changes of taste and smell which re- 

 called those of their original nutritive base. In cultivation of 

 tobacco in Germany it has been sought to get a good quality, 

 chiefly by ground cultivation, and introduction of the best kinds 

 of tobacco. But it is pointed out that failure of the. best 

 success may be due to the fact that the more active fermenting 

 fungi of the original country are not brought with the seeds, and 

 the ferments here cannot give such good results. Experiments 

 made with a view to improvement on the lines 

 apparently proved successful. 



