I'lll-: LKTHAL EFFECT ()K IM kl DISTILLED 



VVATKR ON THF VINKC.AK KKL 



ANCHTLLl'LA ACKTI). 1 



JAMES FRANCIS ABBOTT AND KIIIH1. I KH.I1 KM HARDS 



The question of the toxicity of distilled \\ater for aquatic- 

 organisms appears to be still an open one. An excellent summary 

 of the literature of the subject has been given by Bullot.-' Ringer 

 first noted that distilled water is toxic for a variety of organisms, 

 and attributed this toxicity to (i) an abstraction from the organ- 

 ism of salts which are necessary for its life, or (2) the penetration 

 of water into the cells through osmosis, or (3) the imbibition of 

 water by the "intercellular substance." About the same- time 

 a contrary opinion was advanced by Nageli 1 ' 5 who claimed that 

 it is not the purity of the water but the presence of the slightest 

 trace of copper (even so small a quantity as 1/77,000,000) thai 

 gives water its toxic qualities, whereas if water of this sort is 

 redistilled in glass it loses its toxicity. Shortly after this, Locke 

 questioned Ringer's conclusions and decided that the latter's 

 results too were due to the presence of copper rather than the 

 toxicity of the water and in i895 4 confirmed his belief by experi- 

 ments with the tadpole and Tubifex. Ringer 5 then retestcd his 

 experiments and partially recalled his former conclusions, agree- 

 ing with Locke that "pure water (i. e., that distilled in glass) is 

 completely harmless for the animals in question. This was con- 

 firmed by Jennings for Paramecium, Miss A. Moore for trout 

 and tadpole and F. K. Lillie for Planaria. On the other hand 

 Lyon 6 investigated the action of distilled water on developing 

 Arbacia larvae and found that artificial sea water made up <>! tap 

 water or ordinary distilled water, whether vapori/ed in copper or 

 glass, is very toxic for these larva' although tap water \\lnVh ha- 



From the Zoological Laboratory, Wa-liiii^iun University, M. l.miU. M<>. 

 2 Hullot. Univ. of Calif. Pub.. I'liy^inl.. I.. io<>|. i 



XiiKfli, Dcnksch. d. Schweiz. Naturfor^li. (,< \\<\. 33, [893. 



4 Locke, Jour. Phys., 18, 1895, 319. 

 6 Kinder, Jour. Phys., 22, 1897. 

 'Lyon, Hun.. Mei.i... 6, 190.}, lyS. 



122 



