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THE POPULAR SCIENCE MONTHLY. 



POPULAR MISCELLANY. 



The Disinfection of Streets and Sewers. 



How some of the worthless by-products of 

 chemical works might be turned to good 

 account in disinfecting the streets of our 

 American cities, is shown by Mr. H. G. 

 Debrunner, in the Philadelphia Chemist and 

 Druggist. He is led, by the results of ex- 

 periment, to believe that street-mud and the 

 sewer-water containing the same are the 

 main factors in the distribution of con- 

 tagious disease. This matter could be effect- 

 ually disinfected, and that without extraor- 

 dinary expense, by treating it with certain 

 waste products, such as the mother-liquors 

 of copperas aud alum. Many a factory 

 would be glad to get rid of this refuse, and 

 would give it away for nothing. With these 

 disinfectants, diluted with water to the de- 

 sired strength, the streets should be sprin- 

 kled ; most of the waste substances are so 

 powerful that they may be greatly diluted 

 without losing their efficacy. In street-dust, 

 the author has found, besides the usual in- 

 organic bodies, a number of organic sub- 

 stances as, for instance, glutinous matter 

 coming from abrasions of the hoofs of cat- 

 tle. This matter varies in quantity from 

 one-half to five per cent., and in some dust 

 taken from roads leading to stock-yards it 

 has been found in the proportion of as much 

 as fifteen per cent. It decomposes readily, 

 especially in the presence of water, and 

 microscopic examinations of aqueous ex- 

 tracts of the mud from such localities show 

 living beings of the lowest classes of the 

 vegetable and animal kingdom algae, fungi, 

 and various forms of infusoria. 



The Harpy Eagle. The harpy eagle 

 (Harpyia destructor), of which a spright- 

 ly description is given by Dr. Felix L. Os- 

 wald in the American Naturalist, has its 

 native home in the forests of Southern 

 Mexico. Its common English and its sys- 

 tematic name, as well as its Spanish title, 

 Aquila real (king-eagle), and its old Mexi- 

 can name of " winged wolf," fitly character- 

 ize the rapacity of this bird. It has a square, 

 strong head, armed with a powerful bill that 

 can without any special effort crush a man's 

 finger-bones. Its broad, compact wings are 

 moved by shoulder-muscles of enormous 



strength ; and its stout legs, feathered to 

 below the tarsi, terminate in claws of such 

 extraordinary power and sharpness that 

 they leave their marks on the tough leather 

 of a Mexican saddle, like the bite of a wild- 

 cat. Its plumage is so elastic, so compact, 

 and so firmly imbricated, that buckshot, 

 striking on the wings or the breast of the 

 bird at a certain angle, glance off, or fail to 

 penetrate to vital parts. The fully-grown 

 hen measures about three feet from its crest 

 to the base of the tail, and from six to seven 

 feet from tip to tip of the outstretched 

 wings. The male is somewhat smaller, but 

 the strength of the bird in proportion to 

 its size is altogether abnormal. A tame 

 old harpy eagle once engaged in mortal- 

 combat with a big shepherd-dog, and was 

 only vanquished by a second dog that came 

 to the assistance of his fellow. In a fight 

 of ten minutes the first dog had received a 

 deep gash in his throat (from which he soon 

 bled to death), lost one of his eyes, and the 

 bones of his skull and breast had been laid 

 open in numerous places. In a fight be- 

 tween a harpy eagle and a Mexican lynx 

 which had been crippled by a shot through 

 its haunches, but was otherwise in good 

 fighting condition, the bird was torn to 

 pieces, but the lynx did not survive him 

 many minutes, having been literally flayed 

 from its shoulders to the tip of the nose. 

 The following narrative shows the bird's 

 tenacity of life : A Mexican miner, before 

 daybreak one morning, in the mountains 

 near Orizaba, surprised a pair of harpies, 

 and with a cudgel knocked down one of 

 them, which flew directly at his head. The 

 miner now dispatched the bird as he thought, 

 with a few well-aimed whacks, and, shoul- 

 dering his game, resumed his journey toward 

 the valley. Half-way down the mountain- 

 side he reached a steep cliff, and shifted 

 his burden to his left shoulder, to use his 

 right arm to better advantage. But at the 

 most critical moment of the dangerous de- 

 scent he suddenly felt the claws of the eagle 

 at his neck, and, in order to save himself, 

 had to drop his stick, which fell down the 

 cliffs and into the bed of a mountain-torrent. 

 Holding on to the bird with one hand, he 

 managed to reach the foot of the precipice, 

 where he seized the struggling- captive by 

 the legs, and, swinging it up, dashed its 

 head against a rock, till its convulsions had 



