cheese factory, condensed milk factory, or other place in this com- 

 monwealth shall manipulate the Babcock or other centrifugal machine 

 for the purpose of determining the composition or value of milk or 

 cream as a basis for payment in buying or selling, without first ob- 

 taining a certificate from the director of the Massachusetts agricul- 

 tural experiment station, or his duly designated deputy, that he is 

 competent to perform such work. The fee for such certificate shall 

 be two dollars, and shall be paid by the applicant therefor to the said 

 director for the use of the said station. In case any holder of a cer- 

 tificate is notified by the director, or by his duly designated deputy, 

 to correct his use of a Babcock or other centrifugal machine, the 

 actual cost of making an inspection to ascertain if the said person 

 has corrected his use of the said machine shall be paid by the said 

 person or by his employer to the director for the use of the said sta- 

 tion. No holder of a certificate whose authority to manipulate a 

 Babcock or other centrifugal machine has been revoked by the direc- 

 tor of the Massachusetts agricultural experiment station, or by his 

 duly designated deputy, shall thereafter manipulate in this common- 

 wealth any centrifugal machine for the purposes aforesaid. 



Section 4. The director of the Massachusetts 



Director of the agricultural experiment station and his duly 



Experiment Station designated deputy are hereby authorized to 



empowered to issue certificates of competency to such persons 



issue and revoke desiring to manipulate the Babcock or other 



certificates. centrifugal machine as, in the opinion of the 



director or his deputy, are competent to man- 

 ipulate said machines. The said director or his deputy may make 

 and enforce rules governing applications for such certificates and 

 the granting thereof and may, in his discretion, revoke the authority 

 of any holder of a certificate who, in the opinion of the director or 

 of his deputy, or of an inspector of the said director, is not correctly 

 manipulating any centrifugal machine as aforesaid, or is using dirty 

 or otherwise unsatisfactory glassware or utensils. 



