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THE POPULAR SCIENCE MONTHLY. 



exceptional families. The system can not, 

 therefore, be safely recommended for towns 

 in which a large proportion of the people 

 are always ignorant and careless. The tub, 

 cask, or pail system, which is used even on 

 a large scale in England, France, and Ger- 

 many, " is undoubtedly the best method of 

 removal, where towns have neither water- 

 supply nor sewerage." In this system, the 

 refuse matter is allowed to fall into a tub 

 or cask, which is removed, emptied, cleaned, 

 and disinfected by the town authorities at 

 least once a week. At Manchester, Eng- 

 land, sifted ashes are added during use to 

 the contents of the tub, as a deodorizer. 

 This system is successfully employed at 

 Manchester and Rochdale, England, at an 

 expense of $95 per thousand persons, or ten 

 cents per person per annum ; and is recom- 

 mended for villages which can have no gen- 

 eral water-supply. The weakness of it is, 

 that the removal, cleansing, and disinfect- 

 ing of the tubs require constant care and 

 expense, and may be neglected by careless, 

 ignorant, or parsimonious village authorities 

 a weakness rather attributable to village 

 authorities than to the system but under 

 no circumstances could the evils of such 

 neglect be comparable with those of privy- 

 vaults. The system is, however, unavoida- 

 bly inferior to that of sewerage, in that it 

 does not provide for the removal of waste- 

 water and slops. Mr. Gardiner expresses 

 a decided preference for the " separate " 

 system of sewerage, which is adapted to 

 carry off slops alone, to the " combined " 

 system, in which the attempt is made to 

 carry off both slops and storm-water by 

 means of one set of conduits. He regards 

 the separate system as vastly cheaper than 

 the combined, and as very much more 

 wholesome, in that it does not supply the 

 territory for the cultivation of the bacteria 

 that find rich and extensive propagating 

 grounds on the moist, unglazed walls of the 

 large combined sewers. A conspicuous ex- 

 ample of the successful application of the 

 separate system is found at Memphis, Ten- 

 nessee. 



Origin of the Son's Light and Heat. 



Dr. H. R. Rogers, of Dunkirk, New York, 

 has come forward with a criticism of the ex- 

 isting theories of the origin of the light and 



heat of the sun from combustion, mechanical 

 action, or shrinkage of the sun's mass, as 

 insufficient and not adequately supported by 

 the analogies of any facts with which we are 

 acquainted, and has advanced a theory that 

 they are the result of electrical action. The 

 sun, he believes, is a cold body, like the 

 earth, but so constituted and so situated 

 relatively to the earth that a stream of elec- 

 tric currents is constantly passing between 

 the sun and the earth. These currents reach 

 their points of greatest intensity within our 

 atmosphere, where all the manifestations of 

 force which we assign to the sun's surface 

 really take place. Dr. Rogers also believes 

 that the phenomena of gravitation may be 

 traced to the same origin. 



The Germination and Vitality of Seeds. 



Dr. Richard E. Kunze, has collected a 

 number of facts respecting the germina- 

 tion and vitality of seeds, in an essay which 

 was read by him before the Torrey Botan- 

 ical Club last December. Some seeds, to 

 grow, must be planted immediately on ma- 

 turity. Familiar examples are those of the 

 elm and maple, the oak, and most of our 

 common nuts. The seeds of the larkspur 

 {Delphinium formosum), of some gentians, 

 and of Angelica, partake of this character. 

 Spanish chestnuts and filberts, however, 

 have been sent, enveloped in wax, to the 

 Himalayas, and plants from them are now 

 growing there. Seeds of the Victoria regia 

 had to be transmitted from America to Eng- 

 land in water before the first plant was 

 raised that came to perfection. Bosse, a 

 German horticulturist, says that, when seed 

 is to be kept for any length of time, it 

 should be left in its natural covering. Oth- 

 er means of protection are sometimes avail- 

 able to preserve perishable seeds. Acorns 

 will keep, packed in the hard ground, for 

 centuries, and many seeds may be safely 

 kept or transported in honey. Some seeds, 

 like those of the Cucurbitaccce, the balsam, 

 stock, and wall-flower, improve with age to a 

 certain extent. Many seeds are capable of 

 preserving their vitality for years under or- 

 dinary conditions of dry exposure. Experi- 

 ments by M. Alphonse de Candollc indicated 

 that woody species preserved the power of 

 germinating longer than others, while bien- 

 nials were at the opposite end of the scale, 



