104 MONTHLY JOURNAL OF AGRICULTURE. 



Some French philosoplicrs have found that, from the same food, a cow yields 

 in milk twice as much food available to man as a feeding ox will yield in flesh 

 and fat. M. Donne states that there is a striking analogy between milk and 

 blood, and says that he has injected milk into the veins of many animals without 

 causing any injury. From lean cattle, poorly kept, milk is never known to be 

 good. London milk is generally deficient in thick, rich cream. The Durham 

 cows yield a large quantity of milk, and numbers of them are, therefore, kept in 

 London dairies and in the dairy-farms about Manchester. Milk of a rich quality, 

 fit to supply good cream and butter, is generally yielded in small quantity, as iu 

 the case of the Galloway, Guernsey, Hereford, Highland, and Jersey cows. The 

 cows used for the London milk market are mostly of a large size, with short 

 horns, and are distinguished by the name of Hoiderness cattle — from a district so 

 called in the East Riding of Yorkshire. (9). It appears that the entire number 

 of cows kept by the London cow-keepers amounts to 8,500 — namely, 7,200 in 

 Middlesex, 681 in Kent, and 619 in Surrey. Each cow, on the average, yields 

 nine quarts per diem, or 3,285 quarts per annum ; but deducting 285 quarts for 

 suckling, casualties, &:c. gives us a total of 6,375,000 gallons of pure milk to sup- 

 ply the consumption of London and its vicinity. But as the retail venders adul- 

 terate it with at least 120 per cent, of water, the total annual consumption of 

 what is called milk amounts to 15,937,500 gallons. Each Londoner, on the 

 average, consumes annually ten gallons, three quarts, and nearly two pints of 

 milk. The price at which milk is sold to the retail venders varies from Is. 8d. 

 to Is. lOd. for eight quarts ; which, taking it at the medium of Is. 9d. gives a 

 total of £278,906 5s. for the wholesale price, and an annual expenditure, after 

 the assistance of the pump, of £697,265 12s. 6d. According to the occupation 

 abstract of the census of 1841, the number of persons employed in feeding cows 

 and selling milk in London was 2,764. While the milking of cows is going on, 

 the pans should be placed in boiling water. If the milk be strained into one of 

 the hot pans, and covered with another hot pan, proceeding in like manner Avith 

 the whole mess of milk, you will find that you will have double the quantity of 

 good rich cream, and double the quantity of sweet and delicious butter. It has 

 lately become very common, especially in large dairies, to keep milk in zinc 

 bowls, which have been recommended for promoting the formation of a larger 

 quantity of cream, owing to galvanic action ; but the use of them has been at- 

 tended with poisonous effects. 



" I could scarcely have believed," says Dr. Elaines of Berlin, '■ tliat zinc vessels could asrain have 

 come into use for holding fluids used for alimentary purposes, as Vauquelin, forty years ago, 

 proved that such were certain, after a .short time, (when the milk has become sour and the pans 

 themselves sour,) to hold a considerable portion of zinc (and salts of zinc) in solution. I have 

 found by experience that a solution of sugar, which had stood only a few hours, in summer, iu a 

 zinc vessel, contained a considerable amount of zinc salts. Cream will separate more easily from 

 milk kept for a short time in a zinc vessel ; but as the milk will turn acid much sooner than a so- 

 lution of sugar, it is the more to be apprehended that some zinc will be dis.<olvcd. and such milk 

 will be the more noxious, as it is well known that even a small amount of zinc will cause violent 

 spasmodic vomitings." 



The coagulation of milk under the influence of a simple wet membrane is a 

 remarkable phenomenon not easily explained. Berzelius tried a very curious ex- 

 periment with a view of ascertaining the eflfect on the membrane itself. He 

 took a bit of the lining of a calf's stomach, washed it clean, dried it as com- 

 pletely as possible, weighed it carefully, put it into eighteen hundred times its 

 weight of milk, and heated the whole to 120 degrees Fahrenheit. After some 

 little time, coagulation was complete. He then reirioved the membrane, washed, 

 dried, and weighed it again ; the loss amounted to rather more than one-seven- 

 teenth of the whole. According to this experiment, one part of the active mat- 

 ter dissolved from the membrane had coagulated about thirty thousand of milk. 



The experiments of Professor Traill show that the addition of some cold wa- 



(9). This breed is distinguished by its large frame of coai-se bone, and is said to have formed 

 the chief basis of the Durham or "improved Shon-Hom." They were formerly, in Marj-land, 

 called the " Gough breed " of cattle, from their having been imported by Mr. Gough, of Bal- 

 timore. Mr. Scmmcs, of Delaware, had a herd of them, and we have seen many possessing 

 all the charactcrisiics of the breed at " Blakcford," a beautiful estate of the late patriotic Gov- 

 ernor Wright, which has returned to the family, and been highly improved in the posscs- 

 mon of his sou, W. H. D. C. Wkight, Esq. [Ed. Farm. Lib. 



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