NEEDS OP TIIE DAIRY. 049 



" try .all things and hold fast that which is good." The factory, 

 when no longer needed for experimental purposes, would be worth 

 its cost for an individual or a company to run for their own gain. 

 In this way the desired end would be reached in a safe and 

 economical manner, and who can doubt the vast benefit it would 

 be to our great dairy interest? 



Rennet. One of the most important things in cheese-making is 

 rennet, and I do not think it is taken sufficiently into considera- 

 tion by dairymen generally. Fur the purpose of further illustrat- 

 ing the importance of bringing science to our aid and wedding it 

 to practice by a series of properly conducted experiments, and 

 also for impressing upon your minds something of my own ideas 

 of the attention we ought to pay to the subject of rennet, I must 

 detain you by the recital of a few facts. 



Two of the most valuable papers ever given to the dairy public 

 were read before the American Dairymen's Association, at its 

 convention in 1869. One of them was read by Mr. L. B. Arnold, 

 of Tompkins County, and was entitled, " Rennet — Its Nature and 

 Use; 7 ' the other was read by Prof. Geo. C. Caldwell, of Cornell 

 Universit} 7 , and was on " Fermentation and Putrefaction in their 

 Relations to the .Manufacture of Cheese." I will first give the 

 substance of Mr. Arnold's paper. After a twenty-five years' 

 search for the active principle of rennet, he found it to consist of 

 microscopic globules, so small that they could with great difficulty 

 be separated from the liquid prepared for use in cheese-making. 

 But by making a filter of a piece of charcoal, he succeeded in 

 catching the microscopic globules, onlythe pure brine, destitute 

 of any coagulative virtue, passing. These globules are about the 

 specific gravity of milk. They begin to break and disappear at a 

 temperature a little above blood-heat, and are all destroyed at a 

 temperature of about 140°. Acids and alkalies do not affect them 

 if weak, but destroy them if strong. On examining the inner 

 lining of the calf's stomach, he found it "nearly as porous as 

 honey-comb," to use his own expression. These pores were the 

 mouths of tubes opening into the stomach, and the tubes were full 

 of these globules, those at the mouth being more developed and 

 larger than those following behind them. These globules do not 

 mix much with the gastric juice when the stomach is empty, but 

 adhere to the surface, forming a delicate, light flesh-colored coat- 

 ing, which easily washes off or flakes off when the stomach is 

 handled. lie says : " The first soakings of a stomach produce a' 



