156 Summary of Agricultural Experiments, [may, 



(about 0*19 kilo, per cow per day) took place after feeding with the 

 richer ration, and in three cases the yield changed to an insignificant 

 extent; in these four cases the weight of fat in the milk sank in a 

 marked degree. In another case, a notable diminution in the yield 

 (1*05 kilo, per cow per day) took place, but here there was an increase 

 in the fat (12 grammes per cow per day); this was probably attributable 

 to the fact that a very scanty ration was being fed. In the remaining 

 five cases the yield diminished and also the fat content (with one 

 exception, where it remained unaltered). 



3. The fat-content of the milk after the addition of fatty food was 

 sometimes higher and sometimes lower than with the poor ration. 

 With a marked diminution in the quantity of milk, the percentage 

 of fat rose, but with a smaller decrease it fluctuated but little; when 

 the yield remained stationary or rose slightly, the fat-content decreased. 



4. Fat supplied in the form of rice-meal changed the character of 

 the butter-fat as measured by the Reichert-Meissl number, &c. 



5. The individuality of the cows was very marked, and every variety 

 of effect was produced in single cases by the change in food. 



The experiments as a whole agree in their average results in showing 

 that no economic advantage is to be obtained by increasing the fat 

 in the food above the quantity in a standard ration. Apart from 

 exceptional cases, the quantity of fat in the food of milking cows 

 should be kept within moderate limits, and an equivalent amount of 

 carbo-hydrates should be given instead of large quantities of fatty 

 foods. As feeding stuffs rich in carbo-hydrates are generally cheaply 

 produced on the farm, whereas fatty foods can only be obtained by 

 purchase, and as, moreover, combinations of carbo-hydrate foods con- 

 taining a moderate amount of fat have a better effect on cows than a 

 ration rich in fat, the general tendency of the foregoing experiments 

 is towards cheapness in production. 



Manufacture of Tomato Ketchup without Preservatives (U.S. Dept. 

 of Agric, Bureau of Chemistry, Bull. 119). — This bulletin describes the 

 methods of making tomato ketchup on a commercial scale, and gives 

 the results of a number of experiments on the action of preservatives, 

 and the length of time the product will keep under varying conditions 

 of manufacture and temperature. The results showed that ketchup 

 can be made satisfactorily without preservatives. The mould which 

 develops in ketchup is described and illustrated. Tests were made to 

 ascertain the temperature at which its vitality is destroyed. 



Effect of Formaldehyde upon Digestion and Health (U.S. Dept. of 

 Agric, Bureau of Chemistry, Circ. 42). — The use of formaldehyde as 

 a preservative in food is usually condemned, but it is stated in this 

 publication that it is still advertised for this purpose in the United 

 States under its own and other names. The results are given of careful 

 experiments conducted in 1904. Twelve healthy men were selected and 

 kept under observation for 35 days; in the first period of 10 days their 

 normal condition was ascertained; in the second period of 15 days the 

 preservative was administered ; in the third period of 10 days the after- 

 effects were noted. 



The conclusion arrived at by an examination of all the data was 

 that the admixture of formaldehyde with food is injurious to health, 

 even in the case of healthy young men, so that it is probable that in 

 the case of infants and children the deleterious effects would be more 



