Sanitary engineering : a series of lectures given before the School of military engineering at Chatham, 1876 / by J. Bailey Denton.

  • John Bailey Denton
Date:
1877
Catalogue details

Licence: Public Domain Mark

Credit: Sanitary engineering : a series of lectures given before the School of military engineering at Chatham, 1876 / by J. Bailey Denton. Source: Wellcome Collection.

    439/516 (page 367)
    3H7 APPENDIX C. ON THE EFFECTS OF IMPURE WATER ON THE ANIMAL ECONOMY. [Extract from the Report of Dr. Hoffman and Professor Blyth, addressed to the General Board of Health in 1856.] Very little is known of the nature of the ill-defined substances which constitute the organic matter generally found in water. Berzelius distinguishes two substances—crenic and apocrenic acids—which slightly differ in their chemical deportment; but these two bodies are as yet scarcely chemically examined, and much doubt still hangs over their individuality, and even over their exist- ence. The organic matter in water has been divided into nitrogenous and non-nitrogenous matter; but all we know is that certain varieties of the organic matter found in water contain nitrogen, which is readily shown by treating them with hydrate of potash, when abundance of ammonia is evolved. The opinions of chemists are divided as to the manner in which organic matter in water is capable, under certain conditions, of pro- ducing a deleterious effect upon the animal economy. But it is now generally admitted that the substances which constitute the organic matter of water act injuriously, by no means in consequence of being poisonous themselves, but by undergoing those great pro- cesses of transformation called decay and putrefaction, to which all vegetable and animal matter is subject, when no longer under the control of vitality, either in plants or animals. These putrefactive processes either give rise to the formation of poisonous bodies, or they act simply as ferments, generating similar processes of decom- position in the substances composing the animal organism.' Now, with special reference to the last mode of action, it is well established by general experience that nitrogenous substances are infinitely more liable to undergo putrefaction than organic bodies from which nitrogen is absent. And hence the very general and correct opinion that the deleterious character of organic matter in water is propor- tionate to the amount of nitrogen which it contains. Could this nitrogen be estimated with any degree of accuracy, such an estimate would certainly afford the most satisfactory element in the examination of the organic matter.