September 2, 1887.] 



SCIENCE. 



117 



to get rid of refuse-matters, and not to see how long we can keep 

 them about our houses in a presumed harmless condition. The 

 Rivers Pollution Commissioners in their first report, 1868, have no 

 hesitation in pronouncing the dry-earth system, however suitable 

 for institutions, villages, and camps, where personal or official regu- 

 lations can be enforced, entirely unfitted to the circumstances of 

 large towns. 



The subject of sewerage is very fully treated. In the considera- 

 tion of the separate system, that at Memphis, Tenn., and Pullman, 

 111., are mentioned and described. The best method of sewer-ven- 

 tilation is still undetermined in this country, and the sanitary journals 

 are at the present time discussing the subject with a good deal of 

 earnestness. On this point Dr. Corfield says that the very common 

 plan of ventilating sewers by means of untrapped rain-water pipes 

 from the roofs of houses is extremely dangerous. These pipes are 

 often veiy loosely jointed, and the air rising from the sewer will 

 escape through every such joint, possibly into bedrooms ; and in 

 many cases the open head of the pipe is just beneath a dormer or 

 attic window. During heavy rain the rush of water down these 

 pipes will force the air of the drain into the interior of the house 

 through trapped or untrapped openings. He also condemns the 

 practice of ventilating the sewers by means of the soil-pipes of 

 houses, as there is constant risk of the escape of sewer-air 

 through defective joints into the interior of the house. The house- 

 drain should pass through a disconnecting chamber with an air inlet, 

 and be trapped before entering the sewer. Connecting the sewers 

 with furnace chimneys is also condemned. The Shone, Liernur, 

 and Berlier systems of sewerage are described in a concise but 

 thoroughly intelligible manner. 



Among other interesting topics discussed, and which we are com- 

 pelled to pass over for want of space, are the sanitary aspects of 

 the water-carriage system, the value of sewage, the injury which 

 it works to rivers, the pollution of drinking-water, the discharge of 

 sewage into tidal waters, the straining and precipitation of town- 

 sewage, filtration, irrigation, and the treatment and utilization 

 of manufacturing-refuse. In speaking of the influence of sewage- 

 farming on the public health, the author states, that, as far as 

 nuisance is concerned, there is no doubt that if irrigation farms are 

 badly managed they may be made a nuisance to the neighborhoods. 

 Ordinary sewage is only in a very slight degree offensive when 

 fresh. What is really the most offensive part of sewage farms is 

 the black slimy mud which collects along the sides of the carriers 

 when the sewage is not filtered before being sent to the fields. It is 

 advisable that sewage should be filtered and strained in the man- 

 ner practised at several places. There is no reason to spread a 

 layer of comparatively worthless and necessarily offensive filth over 

 the surface of the soil. There is good reason to expect that the 

 utilization of the sewage of towns on the land near them, while pre- 

 venting the pollution of drinking-water, and the spread thereby of 

 cholera and typhoid fever, will at the same time maintain the purity 

 of the atmosphere around and about the towns, and that the result 

 will be, especially when combined with that produced by the 

 increased demand for labor and the more plentiful supply of food, a 

 diminution of the general death-rate. 



The late Dr. Cobbold had great fear that entozoic diseases would 

 be spread by means of sewage irrigation. Although this possibil- 

 ity has been borne in mind ever since Dr. Cobbold drew attention 

 to it in 1865, there are no facts reported which connect entozoic 

 diseases with sewage irrigation. Dr. Corfield summarizes his 

 views on the question by saying that it has not yet been shown that 

 sewage irrigation has ever increased the amount of entozoic disease 

 in men or cattle. Still less that it is likely to do so to a greater e.x- 

 tent than any other method of utilizing human excrement ; and 

 were this shown to be the case, the danger would be to a great 

 extent obviated by some preliminary treatment, with a view to the 

 separation of the suspended matters. 



The Treatment of Sewage. By Dr. C. M. Tidy. New York, 

 Van Nostrand. 24°. 



This little book, which is one of Van Nostrand's ' Science 

 Series,' contains in a very concise form a great deal of valuable in- 

 formation on the subject of which it treats. It goes over necessarily 

 much of the same ground as Corfield's ' Treatment and Utilization 



of Sewage,' a review of which we have already given, but in a much 

 more condensed form. 



Dr. Tidy, in marked contrast with Dr. Corfield, thinks that there 

 is danger that entozoic diseases may be communicated to both man 

 and beast by means of the products of sewage farms. He says that 

 the fact has always been recognized that entozoic diseases have an 

 external origin ; i.e., that the ova or parasites come from without, 

 and are not generated within, the human body. Millions of ova are 

 voided with every segment discharged by the person afflicted with 

 tapeworm, each ovum being capable of producing a measle in the 

 flesh of an animal, and each measle a tapeworm in the body of the 

 man. He has seen watercresses and celery grown on sewage 

 ground, having a quantity of dried sewage matter deposited on the 

 stems, and he has, with more than a cook's patience, tried to wash 

 this matter off, but the tenacity with which it sticks upon the sur- 

 face of the vegetable when once diy is perfectly astounding. It 

 should be remembered in this connection that these vegetables are 

 eaten in an uncooked state. The grass covered with sewage, eaten 

 as it is with rapacity by the cattle, infects their bodies with the 

 larval parasite. Thus the meat is measly, and measly meat, except 

 for efficient cooking, means tapeworm to the human subject. Per- 

 haps a similar stoiy might be told of trichina, with its ten times 

 greater danger. The farm, therefore, that receives sewage must be 

 more liable to produce measly meat than the farm that does not 

 receive it. 



In opposition to these views of Dr. Tidy we have the opinion of 

 Dr. Corfield, already referred to, and also that of the British Asso- 

 ciation Committee. This committee made experiments to deter- 

 mine this very question of the distribution of entozoic disease by 

 means of sewage irrigation. Dr. Cobbold, at the request of this 

 committee, examined the carcass of an ox which had been fed for 

 two years on sewage-grown grass, and reported the perfect freedom 

 of that animal from internal parasites of any kind, but explained 

 this freedom in a manner which to his mind did not affect the main 

 question. The committee did not accept this explanation, but in 

 their report say that it appears as far as this one case goes (and it 

 is certainly as conclusive as a single case could possibly be), there is 

 no evidence that entozoal forms of life are to be found upon the 

 farm at all, in any stage of their existence, or in the flesh of an 

 animal fed exclusively for twenty-two months on sewaged produce 

 grown on the farm. This report was made in 1871, but we have 

 Dr. Corfield's statement that since the date of that report no facts 

 have been recorded connecting entozoic disease with sewage 

 irrigation. 



It would be interesting to know whether Dr. Tidy or others have 

 any evidence to the contrary. It would seem as though the system 

 had certainly been in practical operation long enough to have set- 

 tled this question. 



It is a matter of regret that the publisher of Dr. Tidy's book has 

 not given the reader a table of contents or an index. In order to 

 ascertain what it contains it must be read through from title-page 

 to colaphon, and as a book of reference its value is greatly dimin- 

 ished from this omission. 



NOTES AND NEWS. 



A Sanitary Convention was held at Traverse City, Mich., 

 Aug. 24 and 25, under the auspices of the State Board of Health. 

 The objects of the convention were the presentation of facts, 

 the comparison of views, and the discussion of methods relating 

 to the prevention of sickness and deaths, and the improvement 

 of the conditions of living. It was not a doctors' convention, but 

 for the people generally. Among the many subjects which were 

 presented and discussed were the following : disposal of waste in 

 Traverse City by sewerage and otherwise, the present and future 

 water-supply of Traverse City, the best methods of warming and 

 ventilation, the work of the village health-officer, the money value 

 of sanitary work, the prevention of contagious diseases, school 

 hygiene, foods and their adulterations, the drink problem, and the 

 prevention of insanity. 



— In the letter on ' Chrome considered as a Poison,' by Charles 

 Harrington, in last week's Science, centimetre (p. 105, col. 2, 4th 

 line) and centigram (p. 106, col. 2, 21st line) should read 'gram.' 



