POPULAR MISCELLANY. 



759 



the fed side. The seeds being ripe at the 

 beginning of September, all the flower- 

 stems were gathered, and the plants of 

 three plates were picked out of the moss 

 and carefully washed. The other three 

 plates were left undisturbed : the relative 

 number of plants which will appear in the 

 spring on their " fed " and " starved " sides 

 will be a means of estimating the relative 

 quantities of reserve material stored up. 

 Mr. Darwin gives in the following table the 

 results of counting, measuring, and weigh- 

 ing, the various parts of the two sets of 

 plants : 



Ratio between the number of starved 



and fed plants 100 : 101.2 1 



Ratio between weights of the plants ex- 

 clusive of flower-stems 100 : 121.5 



Total number of flower-stems 100 : 164.9 



Sum of the heights of the flower-stems 100 : 159.9 



Total weight of flower-stems 100 : 231.9 



Total number of capsules 100 : 194.4 



Average number of seeds per capsule . . 100 : 122.7 



Average weight per seed 100 : 157.3 



Total calculated number of seeds pro- 

 duced 100: 241.5 



Total calculated weight of seeds pro- 

 duced 100 : 379.7 



New Process of Sugar-Manufacture. 



Mention is made in the Revue Scientifique 

 of a new process for sugar-manufacture, in- 

 vented by Prof. Loewig, of Breslau, which 

 greatly simplifies the work. Instead of using 

 lime to defecate the liquor, then having re- 

 course to a double carbonization by car- 

 bonic acid, with a view to eliminate this 

 lime in the shape of lime carbonate, and 

 lastly filtering the carbonated liquor through 

 animal charcoal processes which allow 

 about one-third of the beet-sugar to be 

 transformed into molasses. Loewig simply 

 adds to the crude liquor hydrate of alumina 

 which he has discovered the means of pre- 

 paring on the large scale. This hydrate of 

 alumina retains the coloring albuminoid and 

 nitrogenized matters, forming with them a 

 black scum which is removed. All that 

 remains to be done is to concentrate the 

 almost absolutely pure sugary liquid which 

 remains. If this process proves successful, 

 it will revolutionize the sugar-manufacture. 



Intensity of Different Colored Lights. 



Prof. O. M. Rood describes, in the American 



1 In all cases " starved "=100. 



Journal of Science, a simple method devised 

 by him for comparing the intensities of light 

 of different colors a problem that has long 

 been considered one of the most difficult in 

 photometry. To measure the luminosity of 

 vermilion, for example, he attaches a cir- 

 cular disk of vermilion cardboard to the 

 axis of a rotation apparatus, a smaller cir- 

 cular disk of black-and-white cardboard 

 being simultaneously fastened in the same 

 axis, so that by varying the relative propor- 

 tions- of the latter a series of grays might 

 be produced at will. First the compound 

 black-and-white disk is so arranged that, 

 on rotating the machine, a gray decidedly 

 darker than the vermilion is produced. Then 

 the gray is gradually lightened, till the ob- 

 server becomes doubtful as to which is the 

 more luminous, the gray or the vermilion ; 

 the angle occupied by the white sector is 

 then measured. Next, a decidedly more lu- 

 minous gray is compared with the vermilion, 

 and its luminosity gradually diminished till 

 again there is doubt as to which of the two, 

 the gray or the vermilion, is the more lu- 

 minous ; and then, again, the white sector 

 is measured. The mean of ten such experi- 

 ments showed that when the luminosity of 

 both disks was the same, the white sector 

 of the black-and-white disk was 23.8 of its 

 whole area, and hence that the luminosity 

 of the vermilion cardboard was in the same 

 ratio, namely, 23.8 per cent, to white. 

 Proper allowance was made by Prof. Rood 

 for the amount of white light reflected by 

 the black disk. The relative luminosity of 

 other colors may, of course, be ascertained 

 in the same way. 



Causes of the Chinese Famine. Accord- 

 ing to a correspondent of the London Specta- 

 tor, Frederick H. Barbour, the famine now 

 prevailing in the northern provinces of China 

 began in the fall of 1875. Its immediate 

 cause was the long absence of rain, but the 

 phenomenon to which it was and still is 

 primarily due is the gradual desiccation of 

 the vast plains of Chi-li and Shang-Tuns, 

 a process which, commencing in the table- 

 lands of Central Asia, has now reached 

 the densely-peopled northern provinces of 

 China. Mr. Barbour has for the last two 

 years been in constant communication with 

 the famine-stricken districts, and the letters 



