128 



SCIENCE. 



[Vol. XIV. No. 342 



Quarry, near Philippeville, in Belgium, where fifteen thousand cu- 

 bic feet of marble are extracted yearly with a thirty horse-power 

 Engine, and only thirty hands in summer and twenty in winter, be- 

 sides the lads who tend the wire-cords. The system is also em- 

 ployed at granite and marble quarries in France, Germany, Spain, 

 Italy, Algeria, Tunis, and other countries, where it is said to be 

 giving satisfactory and economical results. 



SEWAGE PURIFICATION. 



A NEW process for the purification of sewage, under patents 

 granted to the firm of Jagger, Son, & Turley, of Halifax, England, 

 was recently experimented with at the corporation sewage works of 

 that city. The apparatus employed is described as follows. A 

 carbon filtering medium is obtained by reducing to a carbonized 

 state dry ashpit refuse which contains a large proportion of animal 

 and vegetable matter. The refuse is placed in a carbonizer, where 

 it is allowed to remain until the whole mass is charred by a pro- 

 cess of slow combustion. After the carbonized material is with- 

 drawn from the carbonizer, it is sifted by means of a circular rid- 

 dle ; and the cinders and a small percentage of clinkers are Laid on 

 one side for use in forming the bottom layers of the filters. The 

 finer grades given out by the riddle, composed principally of char- 

 coal and a small percentage of ashes, are placed as an upper layer 

 of a shallow filter bed, about four inches in thickness. 



A small carbonizer has been erected at Halifax, and a filter of 102 

 superficial yards laid down. The filter is two and a half feet deep, 

 it has a six-inch concrete bottom, and brickwork sides joined in 

 cement. The filter is divided by a fourteen-inch wall, underneath 

 which is laid a channel for conveying away the effluent. The bot- 

 tom course of brickwork of the central wall is open jointed to al- 

 low the effluent to pass from the layers of cinders to the channel. 

 The filter bed is formed as follows. At the bottom is placed a six- 

 inch layer of rough material, which may be clinker or broken bricks 

 or stone. Above this layer is placed another composed of one-inch 

 cinders laid three inches thick ; then follows a layer three inches 

 thick of quarter-inch cinders, and finally a layer of carbon four 

 inches thick, giving a total thickness of sixteen inches. The filter 

 is worked with a six-inch head of sewage. The sewage is con- 

 ducted to the filter by a six-inch pipe, having branches, the pipe 

 being laid on the top of the central wall. Under each branch is 

 placed a floating splash-board, which prevents the sewage washing 

 a hole through the filtering material. The sewage fiows over and 

 through the carbon. The effluent is clear, inodorous, and color- 

 less, and has been proved by analysis to be very pure. The or- 

 ganic matter in suspension was 417.2 grains per gallon in sewage, 

 and 1. 12 grains per gallon in effluent. The albumenoid ammonia 

 in solution was also reduced from 0.280 grains per gallon in sew- 

 age to 0.007 grains per gallon effluent. 



The manner of dealing with the sewage is as follows. Across 

 the, outfall sewer are placed a series of wire-work baskets filled 

 with cinders of different grades, to arrest the grosser floating solids. 

 The sewage then flows to the filter-bed, where the purification of 

 the sewage is accomplished. No chemicals whatever are used. 

 The filter-beds will work at a rate of from 240 to 300 gallons per 

 superficial yard per day, according to the density of sewage treated. 

 An acre of filtering surface will be ample for dealing with the sew- 

 age from 30,000 persons, or say, i ,000,000 gallons per day. The 

 land required for this process is only one two-hundredth part of 

 that required for broad irrigation, or one-fortieth that required for 

 combined precipitation and filtration. The capital cost for this 

 process will be about $340 per thousand inhabitants up to a popu- 

 lation of fifty thousand, and the annual working expenses for col- 

 lecting and disposing of refuse and purifying sewage, inclusive of 

 interest on capital and royalty fees, about sixteen cents per head of 

 population. 



This process solves the sludge diflSculty. No chemicals being 

 used, no weight is added to the solids in the sewage ; the grosser 

 solids are arrested in the cinder baskets, and the finer solids 

 are deposited on the top of the filters in the form of a thin skin 

 After a filter has worked for twenty-four hours, the flow -into that 

 particular filter is stopped, the moisture allowed to drain off, and 

 the deposit removed by a scum plow, a little fresh carbon is laid, 



and the- filter is then again ready for work. By a simple mechani- 

 cal contrivance, a filter of one hundred yards can be cleansed and 

 re-charged in ten minutes. The average weight of sludge made 

 per million gallons of sewage treated by chemicals is twenty tons. 

 In place of a semi-fluid, offensive sludge, by this carbonized refuse 

 process, there remains a manure uninjured by chemicals, which 

 can be carted away as it is removed from the filters, and which will 

 equal in bulk seven and a half tons per million gallons treated. 



HEALTH MATTERS. - 



Leprosy. 



At a recent meeting of the Epidemiological Society of London 

 a paper was read by Dr. P. S. Abraham, on leprosy, of which the 

 Lancet gives the following abstract. With the exception of the 

 case recently brought forward in Dublin, no British society has 

 lately had the subject under consideration. Its importance in 

 British medicine is, nevertheless, well indicated by the fact that the 

 Royal College of Physicians of London has its " leprosy com- 

 mittee," which, in view of the fact that there is increasing evidence 

 respecting the communicabillty of leprosy, has just recommended 

 a full and searching scientific investigation into the whole matter. 



Dr. Abraham demonstrated on a map the wide prevalence of the 

 disease, especially in the British Empire, and remarked that it is no 

 wonder that the subject is coming to the front. He hoped that 

 the inquiry urged by the College of Physicians would be sanctioned 

 by the government, not only to set at rest, if possible, doubtful 

 points regarding the causation of the disease and the desirability 

 of preventive measures, but also to allay a possible emotional scare 

 on the part of the British public. From the insufficiency of data it 

 is difficult to say accurately whether leprosy be really increasing or 

 decreasing in many of the British colonies. In many cases we 

 have to rely chiefly upon general impressions. Even the death re- 

 turns cannot be depended upon always, for they are frequently, as 

 in Jamaica, uncertified by qualified practitioners ; and we must 

 remember the natural and universal tendency on the part of the 

 sufferers and their friends to conceal their affliction. The belief in 

 the increasing spread of leprosy at the Cape of Good Hope was so 

 strong that a leprosy repression act was passed in 1884. From 

 the numerous medical reports which Dr. Abraham quoted there 

 cag be little doubt that the disease is realty on the increase in South 

 Africa. It probably is spreading, but in a less marked manner, in 

 the West Indies ; and on the whole, in India, especially in certain 

 districts. 



The articles which are now appearing in the Anglo-Indiaji press 

 indicate that the public mind is. becoming somewhat inflamed over 

 the matter ; and that there is some cause may be inferred from the 

 large amount of official attention which has been for some time 

 past directed in India to the matter. Dr. Abraham quoted the kte 

 resolution (September, 1888) of the Indian government, stating that 

 a measure of rigorous segregation would be repugnant to public 

 opinion, and recommending for the present the grant of medicine 

 and charitable relief in voluntary hospitals and asylums. A short 

 history of leprosy in Hawaii was then given, the latest information 

 having only just come to hand. He pointed out that, in spite of 

 the efforts at isolation, the disease had enormously increased since 

 1865. The author gave an account of his visit last year to the 

 Norwegian leper asylums, and gave particulars relating to the 

 treatment of the patients, and the views with which he was favored 

 by Drs. Danielssen, NickoU, Kaurin, and Daud, who were in charge 

 of the asylums at Bergen,, Molde, and Trondhjem. He showed 

 curves indicating the relations between the gradual decrease of the 

 disease throughout the country and the number of patients in the 

 hospitals. 



With regard to leprosy in Great Britain and Ireland, he referred 

 to cases he had recently seen in London. Through the kindness 

 of Mr. Larder he was able to exhibit to the Society two fairly 

 typical examples of the chief varieties of the disease, one the 

 "nodular dermal form," and the other the so-called " ansesthetic " 

 form. The latter case was that of a man sixty-four years old, a 

 meat salesman, of English parentage, and born in London. When 

 young he had been a sailor in the Mediterranean and in the Baltic, 

 but had not been out of London for upwards of forty years. Until 



