TESTIMONY OF BENJAMIN SILLIMAN. 123 



ated in this matter was Soubeiran, Kayer, Gueneau De Mussy, 

 Bouchardat, and Orfila, who was the reporter ; the employment of 

 the creamometer or graduated etrouvette, which was an instrument 

 necessary for the lacto-densimeter in order to determine the cream ; 

 he then goes on to give more minute observations with regard to the 

 methods of examination, and adds as follows : "We only occupy 

 ourselves here by considering things practically essential alike for 

 the security of the vender, and also in efforts which shall be suffi- 

 ciently expeditious ; we do not speak of those methods the manipu- 

 lations of which are more or less complicated, which belong necessa- 

 rily to the domain of the laboratory, the shortest of which demands 

 generally from fifteen to thirty minutes." He then goes on to describe 

 particularly the method of construction of the lactometer or lacto- 

 densimeter upon pages 4 and 5, and there is the original figure 

 which has been copied into so many books ; if you so desire it I 

 will translate more of this description, but it w^ould occupy some 

 time ; there are points which I have not yet spoken of. 



Q. I desire you to translate such portions as you deem necessary 

 to show that Quevenne advocates the use of the lactometer as it is 

 used by the Board of Health, I mean in the same manner ; the quo- 

 tations which show that that book supports the lactometer alone, 

 and not the lactometer and the hydrometer. A. He goes on to show 

 how to apply a table for the corrections of temperature where the 

 instrument is used at another than a standard of temperature fifteen 

 degrees centigrade. Upon page 11 the author says the degree 

 which the lacto-densimeter should mark in the milk, Quevenne has 

 found that upon thirty-two specimens of milk collected under very 

 varying conditions, the mean degree by the lacto-densimeter was 

 30.8, that two milks which were found to weigh 27.5, and another 

 the higher figure of 36, the minimum was 29 and the maximum 345. 

 Since this time we have had occasion to continue the examination 

 of other milks taken under circumstances equally varied for place, 

 for season, for food, for the kind of life, whether in the open air or in 

 the stable, for the age of the animal and that milk, etc. ; by way of 

 explaining that last statement it would be proper to add, that on the 

 previous page the author calls attention to the fact that there is a 

 variation in the density of milk from the moment when it is drawn 

 or just after it is drawn, and after it has stood six hours ; it is not 



