242 Proceedings of the Royal Irish Academy. 



XL. J^OTES OF SOiEE OBSEEyATIO>'S OX jS'lTEIFICATION . By EdITCXD 



"W. Datx, a. M., M. D., Professor of Forensic Medicine, Eoyal 

 t College of Surgeons, Ireland, etc. 



[Eead, May 12, 1879.] 



A GOOD deal of attention, on the part of chemists, has of late been 

 given to the subject of nitrification, or the formation of nitrites and 

 nitrates under different circumstances. This has arisen, in a great 

 measure, from the observations of MM. Schloesing and Miintz,^ 

 ■vrhich "were laid before the Academy of Prance about tTvo years ago. 

 From the researches of those gentlemen, they arrived at the conclu- 

 sion that nitrification was due to an organised ferment, and that it was 

 probably the office of some of the low forms of vegetable life to produce 

 those oxides of nitrogen under different circumstances. And the sub- 

 sequent investigations of "Wamngton, Storer, and of other chemists, 

 would appear to go far to con fir m the correctness of their theory of 

 nitiification, at least under the conditions in which their experiments 

 were made. Though there exists, no doubt in many cases, an inti- 

 mate relation between the formation of nitrites and nitrates, and the 

 development of certain organized germs, still as far as my observa- 

 tions go, I do not think that there is sufficient proof to show that 

 their development in such instances is the cause of nitrification, and 

 not, rather, one of the cii'cumstances attendant on that process. 



My experiments, however, were made not with a view to deter- 

 mine that question, but in reference to the detection of animal im- 

 purities in potable waters, and to ascertain the circumstances which 

 were favourable or otherwise to the formation of nitrites and nitrates 

 in waters which were so polluted, as the presence of such salts is 

 generally regarded as indicating previous sewage contamination, and 

 the drinking of water with such pollution is not only injurious to the 

 health of those who thus employ it, but there exist strong grounds 

 for the opinion which is now very generally entertained, that such 

 water frequently becomes the means of conveying the germs of cer- 

 tain formidable diseases, especially those of typhoid fever and cholera, 

 fi'om its containing the fecal and other emanations of individuals 

 labouring under those maladies, and thus disease and death are often 

 insidiously brought into many homes when such diseases are prevalent 

 in different localities. 



Besides, as the formation or production of nitrates is one of great 

 industrial and agricultui-al importance, any facts which might directly 

 or indirectly enable us to facilitate or hasten that process would be of 

 much practical value. 



1 " Comptes Eendus," Ixsxiv. 301. 



