October, '22] 



DE ONG: HARD WATERS AND SPRAYS 



343 



emulsions or to increase the cleansing power of the laundry water and 

 hence is a waste. Therefore, if a hard water is used in preparing or 

 diluting an emulsion, the hardness must be removed by the use of a 

 preliminary softening agent or by sufficient soap to produce the same 

 result. A slight amount of alkali in the water does not materially 

 retard the action of soap but if excessive quantities of sodium salts 

 are present, the formation of lather is checked. 



Table III. — Summary of Modified Formulas for Making Oil Emulsions With 

 Waters of Varying Degrees of Hardness 

 (Amounts based on 100 gallons of spray mixture) 



The amounts of water softener and soap given are averages of trials 

 which have produced satisfactory emulsions in a number of waters 

 with the degrees of hardness given in columns 1 and 6. These figures 

 indicate the amounts of soap and softener required for making emul- 

 sions with water of a similar type, or the softener alone, if prepared 

 emulsions are used which are not adapted to hard water. 



Some variation from the amounts of softener and soap given will, 

 of course, be necessary for different types of water and oil. The data 

 given are simply the results from experiments where satisfactory emul- 

 sions were secured and hence may be taken as a basis from which 

 to work. It should be remembered, however, that changes in the type 

 of oil, water or softener used means a new experiment, and should be 

 considered as such 



The Relation Between Arsenical Injury and Alkaline and 



Hard Waters 



It has been shown by Headden* and Hayward & McDonnelP that 

 the soluble salts cornmonly occurring in waters, (notably sodium chlo- 

 rid, carbonate and sulphate) if present in more than small quantities, 

 may exert a solvent action on lead arsenate. Headden states^, "that 

 he considers it unsafe to use alkali water as a carrier for lead arsenate," 



* Headden, Wm. P., "Arsenical Poisoning of Fruit Trees." Colo. Bui. 131, p. 220. 

 5 Hayward & McDonnell, "Lead Arsenate," U. S. Bu. Chem. Bnl. 131, pp. 46-49. 



