154 TESTIMONY OF JOSEPH T. O'CONNOB. 



ordinary intelligence may be instructed to use the lactometer and 

 observe its results correctly without understanding the scientific 

 principle upon which it is made. 



Mr. LAWBENCE "We agree that that can be done, but we suppose 

 that if the instrument was constructed inaccurately or badly the 

 results would mislead the person instructed. 



WITNESS The temperature is here, as I take it, sixty-three and 

 a half ; the temperature has gone down because some cold water 

 has been added ; we now let it come to rest ; I shall read it as stand- 

 ing at 85. 



A JUBOB What per cent, of added water ? 



Mr. PBENTICE 33 per cent, of added water. 



WITNESS It has gone down since I read it to 83 ; in an exami- 

 nation of this kind where we are looking around for so many things 

 at once we do not have our minds directed to the business entirely. 



By Mr. LAWBENCE Q. Do I understand 25 or 33 per cent, was 

 added ? A. 33 per cent, of water was added, but in the mixture 

 there is only 25 per cent, of course. 



MB. PBENTICE Pour the milk back into the broad cylinder ; now I 

 wish you would take these two lactometers and put one in each vessel? 

 This is the pure milk, that is to say it ought to be if it came 

 from the cow ; I desire you to withdraw the lactometer from each of 

 those vessels and let the jury see whether or not there is a differ- 

 ence in the appearance of the milk as it runs off the lower bulb in 

 the color and the appearance ; hold it up, please, both together ? 

 (The witness did so.) 



Q. Is that one of the observations that you make in examining 

 the milk, to see the manner in which it runs off, to see the bulb ? 

 A. It is always. 



Cross-examined : 



Q. Dr. O'Connor, if that milk had contained an addition of but 

 15 per cent, of water would you still have been able to notice the 

 difference in the color of the two fluids, the pure milk and the one 

 containing 15 per cent, of water ? A. If any one specimen of milk 

 be adulterated with 15 per cent, of water I certainly think I could 

 cell the difference. 



