It has been settled that it is an offence against St. 1864, c. 122, to sell milk adulterated by water, and that guilty knowledge on the part of the seller need not be alleged or proved. Commonwealth v. Farren, 9 Allen, 489. Commonwealth v. Nichols, 10 Allen, 199.
The defendant in this case contends that the statute is unconstitutional, because it is in derogation of common right. The substance of the argument is this : It is innocent and lawful to sell pure milk, and it is innocent and lawful to sell pure water; therefore the legislature has no power to make the sale of milk and water, when mixed, a penal offence, unless it is done with a fraudulent intent. But it is notorious that the sale of milk adulterated with water is extensively practised with a fraudulent intent. It is for the legislature to judge what reasonable laws ought to be enacted to protect the people against this fraud, and to adapt the protection to the nature of the case. They have seen fit to require that every man who sells milk shall take the risk of selling a pure article. No man is obliged to go into the *266business; and by using proper precautions any dealer can ascertain whether the milk he offers for sale has been watered. The court can see no ground for pronouncing the law unreasonable, and has no authority to judge as to its expediency.
The second section provides for the appointment of inspectors of milk, to analyze or test milk, and make and record a certificate of the result, and it further provides that such certificate when sworn to shall be admissible in'evidence in all prosecutions under the act. A certificate of Dr. White, who was an inspector, was admitted in evidence in this case, and it is objected that the legislature had no power to make it evidence in a criminal case. But it further appears that he was a witness in the case, and testified to all the facts set forth in the certificate. We think this destroys the force of the objection, whatever it might have been otherwise.
Exceptions overruled.