1846.] On the Milk of the Cow. 135 



la mort du safron, and soon destroys the whole crop. The other 

 fungus [pen'ola tomenfosn) is found on the potatoe, kicerne, &c. 

 It turns the roots to a purplish hue. They are both propagated 

 by spawn or fibres, which cling round the roots. All these fungi 

 propagate rapidly, requiring only twenty-four hours to come to 

 maturity. One mushroom will propagate 250,000,000. Plants, 

 Dr. L. says, are generally most affected by superficial fungi after 

 a long drouth. Red ■plants are said to be more liable to mildew 

 than any other. Mr. Bauer has found that steeping grains of corn 

 in lime-water, will cure, or at least, prevent the spread of the in- 

 ternal mildew. There appears, however, as yet, to be no cure for 

 mildew in the roots, but by forming a deep trench round the in- 

 fected plants, and cutting off all communication between them and 

 the rest of the field. — Jimerican Farmer. 



ON THE CHANGES IN COMPOSITION OF THE MILK 

 OF A COW ACCORDING TO HER EXERCISE AND 

 FOOD. 



[Communicated to the Chemical Society of London by Lyon Playfair, Ph.D., 

 Honorary Member of the Royal Agricultural Society of England. Read 

 17th January, 1843.] 



This paper, although published in 1843, is not so generally 

 known as it ought to be, as it is one which is highly practical, 

 and may be advantageously studied by every dairyman. We 

 propose giving a full analysis of its most important facts and 

 principles. The object of the paper is expressed in the heading, 

 though it really takes a wider range than is indicated by its title. 



The first point was to determine the usual composition of milk. 

 Boussingault and Lebel have endeavored to show that milk is 

 constant in its composition, when the aniiTials are fed on matters 

 which contain a constant quantity of nitrogen. Thus, according 

 to the mean of eight analyses, milk is composed of 



Casein, .... 3.2 

 Butter, .... 4.1 

 Sugar, .... 5.1 

 Ashes, .... 0.2 

 Water, .... 87.4 — Boussingault. 



Prof. Plaj^air agrees with Boussingault so far as the casein is 

 concerned, namely, that when the nitrogen in the food is constant, 

 the cheesy part, or the casein, will be so too; but the other ingre- 

 dients will vary. The experiments of Playfair were made upon 

 one cow, of the short horned Durham, whose condition was good. 



