Timely Hints for Farmers. 261 



Package Mfg. Co., Chicago; Cornish, Curtis & Green, Fort At- 

 kinson, Wis. ; F. B. Fargo, Lake Mills, Wis. 



Sulphuric acid which is used may be purchased at almost any 

 drug store, but if a bottling establishment is available it is better 

 to get your supply there ; druggists sell so little of it that it is 

 likely to be weak from long standing. The acid costs, in Arizona, 

 from five to eight cents a pound and that amount is sufficient to 

 test about fifteen samples. 



The writer has found bichromate of potash a satisfactory pre- 

 servative on account of its cheapness and efficiency, and the fact 

 that it colors the milk renders it unlikely to be used by 

 mistake for purposes other than testing. It may be purchased 

 (powdered) of druggists at ten cents per quarter of a pound; this 

 amount should be sufficient for 250 to 300 tests. A 32-short cart- 

 ridge with a wire handle makes a convenient measure and holds 

 the right quantity for keeping a pint of milk a week. 



In purchasing a tester it is always advisable to get a good 

 machine. Cheaper ones than those mentioned above are on the 

 market, but unless it becomes a question of a cheap one or none 

 at all, it is not best to buy that kind. By all means do not get a 

 machine having a friction gear. The accuracy of the testdepends 

 upon the speed at which the bottles are whirled and with a fric- 

 tion gear it is impossible to determine the speed. 



The directions accompanying the tester, if followed, are 

 usually adequate for its successful operation. The following 

 points, however, should be carefully watched : 



1. Sampling the milk. The milk from which the sample 

 for testing is taken must be thoroughly mixed so that the cream is 

 evenly distributed through it. Avoid shaking in such a way as 

 to churn the butter fat. 



2. Strength of acid. The acid should have a specific grav- 

 ity of 1.82 to 1.83. This is determined by the use of a glass float 

 which may be purchased with the machine at a cost of from 35 

 to 75 cents. Acid is weakened by the addition of water. 



3. Temperature of milk and acid. The temperature of the 

 milk and the acid should be from 6o° to 75°F. If you have no 

 thermometer buy one with your machine. No. dairyman should 

 try to get along without one. The writer has found it conve- 



