42 Journal of the Department of Agriculture!. 



Prom these figures it was calculated that the waters contained 

 the following- salts in solution : — 



1. 2. 3. 



Calcivim carbonate — 13.59 32.91 



Calcium sulphate 69.16 74.91 117.96 



Magnesium sulphate 67.35 148.62 200.44 



Magnesium chloride 10.71 — 25.18 



Sodium sulphate — 53.06 — 



Sodium chloride 205.90 135.14 284.31 



These waters also failed to form satisfactory emulsions with a 

 carbolic dipping fluid, a precipitate being formed in tlie water 

 immediately upon addition of the dip. On attempting to use the 

 waters so as to make up solutions of 80 per cent, arsenite of soda of 

 the strength prescribed for dipping, i.e. in the proportion of 3 lb. 

 of the arsenite to 100 gallons of water, 5.71 ounces remained undis- 

 solved in the case of No. 1, 2.86 ounces in the case of No. 2, and 

 2.98 ounces in the case of No. 3. The quantity of water received was 

 insufficient to allow of a complete test with lime and sulphur dips, 

 but as such tests seemed very desirable I suggested (in April, 1913) 

 that further samples of the Calvinia waters be procured for this 

 special purpose. The Secretary for Agriculture looked upon the 

 results above recorded as confirming- suspicions which he had had 

 for some time, and was very anxious that the experiments in connec- 

 tion with lime and sulphur dips should be carried out, and directions 

 were given accordingly. The laboratory had, however, by that time 

 been transferred to the Department of the Interior, and, as far as I 

 am aware, no further steps were taken in the matter. 



About a year previous to the last work on the Calvinia waters, it 

 had been persistently reported from the Kentani district in the 

 Transkei, that solutions of soduim arsenite, made up at proper 

 strength, had failed to destroy ticks, although solutions containing 

 the same proportions of arsenite were said to have yielded good results 

 elsewhere. The presence of salts in the water was suggested as a 

 remotely possible reason of diminished efficiency. Samples* of water 

 from nine different localities in the district were therefore procured 

 and tested with regard to their saline contents with the following 

 results, in grains per gallon : — 



Locality. Total Dissolved Salts. Chlorine. 



Qombolo 40.60 14.2 



Macibe 30.52 11.5 



Nytura 30.24 8.7 



Takazi 52.08 16.9 



Gqungqe , 67.48 . 29.8 



Nxaxo 37.80 10.1 



Godidi 39.48 12.8 



Ndebe 18.76 3.0 



Teko 15.40 2.3 



In addition to the above laboratory examinations, practical tests 

 were made with all these waters for the purpose of ascertaining their 

 suitability for use with sodium arsenite. The results of these tests 

 were satisfactory in every case, no precipitation of arsenic taking 

 place. 



It is apparently still quite uncertain whether calcium, 



