The Dipping of Sheep in so-called Carbolic Dips. o39 



Siic]\ a dip is usually described as non-poisonous, presumably 

 because it contains neither tlie highly corrosive poison phenol nor the 

 violently poisonous arsenic, or, perhaps, because if only moderate 

 quantities of the dip be taken internally, fatal results will not follow. 



Samples of the water actually used in the dipping were not avail- 

 able, because, in making the dip, a little rain-water from the dam 

 was mixed with fountain water; quantities of the fountain water 

 were, however, obtained. Since dam waters are usually softer than 

 fountain waters it may be assumed that the water actually used in 

 mixing the dip Avas somewhat softer than the fountain water. 

 Analysis of the latter showed it to contain : — 



Grammes per 

 100,uOO c.c. 



Sodium bicarbonate 7.9 



Calcium and magnesium carbonates 21.0 



Sodium chloride 0.5 



Free carbon-dioxide 1.87 



The water would be described as a moderately and temporarily 

 hard sodium bicarbonate water. 



Experiments made with this water and dip " A " in the propor- 

 tions 1 to 150 showed that it did not give a perfect emulsion ; that 

 there was a considerable separation of oily globules. 



The following are some of the resnlts of these experiments : — 



Mi.vfu/'es of "A ' ' aru] icaler in the proporfion 1 : 150. 



Mixture. Oils Separated. 



(1) " A " to fountain water 13.5 



(2) Fountain water to "A" 10.9 



(3) " A " to distilled water 3.7 



(4) Distilled water to " A " 3.1 



The emulsioiis were made by thoroiigh mixing and agitation; 

 after they had stood 10 minutes the separated oils were removed and 

 weighed, the removal of them taking- about half an hour to accom- 

 plish. It will be observed that the amount of non-emulsified oils is 

 very considei'able in the case of the fountain water, and appieciable 

 in the case of the distilled water mixtures. It is also obvious that 

 the better emulsions were obtained by adding the water to the dip. 



Seeing that the dip would not give a perfect emulsion with dis- 

 tilled water it appeared that " A " mig-ht be an imperfectly made dip ; 

 that, for instance, not enough soda and rosin had been used in its 

 ])reparation. This Avould not appear to be the sole cause leading to 

 the separation of the oils, for a mixture prepared by adding distilled 

 water that had been recently boiled to an appi'opriate quantity of " A " 

 ^ATe a much less visible separation of oils. 



Now, the boiling' of tiie distilled water would have the effect of 

 driving out any carbon-dioxide gas it contained. A further experi- 

 ment, consisting in passing* through the emulsion a stream of carbon- 

 dioxide, was, therefore, made, and it caused a considerable separation 

 of oils, showing that carbon-dioxide could destroy enrulsions of " A." 

 Its action in this respect would seem to be due, in part, to the fact 

 that it has the property of decomposing cresylates; it has also another 



