Milk, cheese, and butter : a practical handbook on their properties and the processes of their production, including a chapter on cream and the methods of its separation from milk / by John Oliver.

  • Oliver, John (Writer on dairy products)
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Milk, cheese, and butter : a practical handbook on their properties and the processes of their production, including a chapter on cream and the methods of its separation from milk / by John Oliver. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    to the left side of the heart, and being sent out through the arteries to all parts of the system. Certain branch arteries supply the udder or mammary gland with the blood for milk secretion. The udder is a body of tissue of spongy character, divided length- wise into two main parts, called lobes, by a wall of ligament or fibrous tissue which supports the organ. From this wall fibres run through the structure and join the outside coat beneath the skin, so binding the whole well together, and yet, by their elasticity, giving scope for motion and expansion. The cavities which give it a spongy appearance belong to four systems, and connect with tubes which join each other, and enlarge (just as streams join to form rivers), finally opening into the four large milk cisterns situated above the four active teats of the organ. Two of these systems lie .on either side of the ligament, and a cow is therefore said to have four quarters. There are sometimes two other teats, not fully developed, and having no milk-forming organs. Each system is distinct from its fellow, and it is possible for either to fail while the rest yield milk. The tissue is of a grey colour, flushed with the red of the blood. In the cavities referred to above the milk is secreted. They are of globular or pear shape, and extremely small. Each is an independent organ of itself (Fig. 6), and described as an alveolus (meaning a little cavity, plural alveoli). It is lined with epithelium cells a, surrounding and close to which are the blood capillaries b, fed by an artery c, and emptying into a vein d. The cells receive the blood which escapes from the capillaries, and convert certain parts of this into cer- tain parts of milk, while the remainders pass into the in- teriors of the alveoli without practical change. It appears to be reasonably certain that both kinds of blood - cor- puscles, as well as the plasma, furnish the cells with milk- making materials. The red corpuscles alone contain Fe, and this (in Fe„0;,) is present in the ash of milk. A complete decom- position of the constituents of blood, and their reconstitution in new forms, is quite within the range of cell possibilities. There are albuminoids in all parts of the blood, fats mainly in the corpuscles. ( r » t ' f / I Fjg. 6.—Alvkolus.