TESTIMONY OF CHARLES F. CHANDLER. 45 



stances, would fall below 100 on the lactometer graduated by the 

 standard of the Board of Health ? 



(Objected to ; objection overruled ; exception.) 



A. I do not recollect a case in which any cow, under normal cir- 

 cumstances, produced a sample of milk which stood below 1.029, or 

 100, on the lactometer used by the Board of Health. 



Q. Doctor, in regard to experiments and observations made by 

 chemists and scientific men in the determination of the results of 

 scientific inquiry, is there what is called an error of experiment, so 

 that an average has to be taken from a large number of samples ? 

 A. There is. 



Q. Now, sir, is the lactometer a means of determining the qual- 

 ity of milk, or anything besides its specific gravity ? A. The lacto- 

 meter by itself simply indicates specific gravity. 



Q. And nothing else ? A. And nothing else. 



Q. Now, sir, I will be glad if you would show to the Court and 

 jury the manner of using the lactometer ; I ask you to take the 

 milk? 



(The witness here made experiments with milk.) 



A. We simply place the milk in a cylinder and put in the 

 lactometer, so that the bubbles which may form shall be floated 

 over the side to make a clear surface of milk, and we further take 

 care that the upper part of the instrument shall not become cov- 

 ered with milk ; that would, of course, increase its weight, and make 

 it descend to a greater depth ; then we introduce the thermometer to 

 ascertain the temperature. I have not taken care to secure exactly 

 the temperature because it is not intended to proceed against the 

 party from whom this milk was obtained ; the temperature is actu- 

 ally 67, which is 7 degrees above the proper temperature. 



By COUNSEL FOR DEFENDANT Q. "What's the gravity of milk? 

 A. The gravity of the milk is 82 by the lactometer. 



By MR. PRENTICE Q. Was this experiment made on any ratio of 

 temperature and gravity? A. No. The coefficient of expansion for 

 milk is variable, consequently it is not possible to determine before- 

 hand what the conditions by the lactometer will be for a fixed basis 

 of temperature, and a correct reading of the lactometer for deviations 

 from the standard temperature of 60 ; the only safe plan is to cool the 

 milk to 60. Any attempt to correct the lactometer by any standard 



