657 



MILK. 



MILKY WAY. 



633 



MILK, Analysis, and Uses of. 



From this analysis it would appear that milk is a compound fluid, 

 chiefly consisting of oleaginous and albuminous materials, with different 

 salts. 



According to Dr. Prout, " albuminous and oleaginous principles may 

 be considered already fitted for the purposes of the animal economy, 

 without undergoing any essential change in their composition." And 

 thus, by the action of the organs of the parent, the food is brought 

 into a state very favourable for its assimilation in the body of the 

 young, without taxing severely the digestive organs of the latter. The 

 salts present in the milk serve also important uses, especially the 

 phosphate of lime by consolidating the bones, which, at the time of 

 birth, are soft and cartilaginous. The period when lactation in the 

 human offspring should cease must vary with the vigour and progress 

 of development of the infant ; but in general nine months is the proper 

 time for suckling, and its continuance beyond that period is injurious 

 both to parent and child. 



The milk of cows or other animals is extensively used as the food 

 even of adults, and, though insufficient alone, is a, most valuable in- 

 gredient of diet. It is often enjoined as the food of invalids, especially 

 of persons who have a tendency to consumption. 



Milk is also used as an antidote in cases of poisoning by some 

 metallic salts, such as corrosive sublimate, perchloride of tin, sulphate 

 of copper, Ac. 



Though cheese is in general difficult of digestion, fresh-pressed curd 

 i often found to suit the stomach of persons affected with disease of 

 that organ. (See Abercrombie, ' On Diseases of the Stomach.') 



Milk may be brought to a dry state, and powdered, in which con- 

 dition it keeps for a length of time ; and by dissolving it in tepid 

 water an artificial milk may be formed, capable of being used at sea, 

 particularly for children during long voyages. [MiLK, and FOOD, in 

 NAT. HIST. Div.] 



Milk, in its commercial relations, has been affected in a remarkable 

 degree by the opening of railways. Under the old system, London and 

 other great towns had their entire supply of milk from dairies in .and 

 near the towns themselves. [DAIRY.] The adulteration, so much 

 complained of, was due to the small dealers ; the milk was sent from 

 the large establishments in a pure state. Attempts were more than 

 once made to insure the genuineness of the milk sold by retailers, by 

 establishing joint-stock companies, and sending out the milk in locked 

 cans; but the companies failed as commercial speculations. This 

 system, though not superseded, is greatly lessened by the facilities of 

 railway conveyance. Farmers and dairymen within fifty miles of Lon- 

 don can send up milk at an average cost of about three farthings per 

 gallon for freight, and sell it to the smaller dealers. New York and 

 other cities of America, are supplied in a similar way. 



,Much useful progress has been made in so treating milk that it will 

 keep good for a considerate length of time, and thus be available at 

 times and places where cows cannot be kept. We will briefly de- 

 scribe some of the processes adopted. Moore's essence of milk is pre- 

 pared by placing the milk in long ' shallow copper pans, heating it by 

 team to 110 Fahr., adding a little sugar, and stirring for four hours; 

 the milk loses three-fourths of its bulk by evaporation ; and the rest, 

 as a very thick cream, is put into small tin cases, soldered down, 

 steeped in boiling water for a time, and taken out to cool. This milk 

 will keep good for a long period. Blatchfo'rd's solidified milk is thus 

 prepared. About 112 Ibs. of milk are mixed with 28 Ibs. of white 

 sugar, and a teaspoon-fill of )>u-art>onate of soda ; the liquid mixture is 

 exposed for three hours in an enamelled iron pan, to the heat of steam ; 

 while it is at the same time being constantly stirred, and a blast of 

 cool air blown upon its surface. This is continued until the milk is con- 

 verted into a kind of creamy powder, which is cooled, weighed into 



ARTS AND SCI. DIV. VOL. V. 



parcels of 1 Ib. each, and pressed by heavy weights into brick-shaped 

 pieces ; these bricks are grated into powder when the milk is to be 

 used. Grimwade's desiccated milk has a little sugar and alkali mixed 

 with it ; it is heated aud stirred over a hot water boiler until as thick 

 as dough ; then dried into hard cakes, crushed beneath granite rollers, 

 and bottled. This milk was used by Miss Florence Nightingale in the 

 hospitals at Balaklava and Scutari. Fadeuille's desiccated milk is pre- 

 pared nearly in the same way as Grimwade's ; and a suit for infringe- 

 ment of patent was brought by one inventor against the other in 1859. 

 At the Aberdeen Meeting of the British Association, in 1859, the AbbcS 

 Moigno gave a brief description of ^four kinds of milk preserved by 

 methods adopted in France. Villeneuve's is rendered solid by the 

 addition of solid substances ; but it is no longer milk proper. Signac's 

 is a kind of syrup of milk and sugar. Maber's is prepared by putting 

 the milk into a vessel, excluding the air, exposing it to a steam 

 atmosphere of 100 centigrade, and sealing it up in bottles; Moigno 

 found this kind of milk perfectly good after five and a-half years keep- 

 ing. The Abbe 1 brought to Aberdeen some milk which had been 

 prepared by De Pierre's process, the details of which were not fully 

 made public. This milk, unlike others in a prepared state, is liquid. 

 Heat is applied in some peculiar way, so as to remove a sort of diastase 

 or animal ferment which exists in minute quantity in milk, and which 

 is the real cause of its speedy decomposition. The milk brought by 

 Moigno from France to Aberdeen had undergone a good deal of shaking 

 during its travels ; but it was pronounced by Professor Christisou to 

 be perfectly sweet and fresh. 



There are other processes for preserving milk, mostly in a dry or a 

 pasty state ; but the above will sufficiently illustrate them all. Some 

 of the preserved milks are over-sweetened with sugar, while others 

 afford proof that the cheese-making stage has just been touched ; and 

 it is evident that the process requires to be conducted with great 

 precision. 



MILKY WAY. It is desirable, in describing astronomical objects, 

 to keep as close as possible to the words of those who are accustomed 

 to the sight and description of such things. Two passages in Sir John 

 Herschel's ' Astronomy ' will describe the Milky Way, and the theory 

 of it, by Sir William Herschel, with excellent brevity and distinctness. 



" There are not wanting natural districts in the heavens, which offer 

 great peculiarities of character; and strike every observer : such is the 

 Milky Way, that great luminous band which stretches, every evening, 

 all .across the sky, from horizon to horizon, and which, when traced 

 with diligence, and mapped down, is found to form a zone, completely 

 encircling the whole sphere, almost in a great circle, which is neither an 

 hour circle nor coincident with any other of our astronomical grammata. 

 It is divided in one part of its course, sending off a kind of branch, 

 which unites again with the main body after remaining distinct for 

 about 150. This remarkable belt has maintained, from the earliest 

 ages, the same relative situation among the stars ; and when examined 

 through powerful telescopes, is found (wonderful to relate !) to consist 

 entirely of start scattered by millions, like glittering dust on the black 

 ground of the general heavens. 



" If the comparison of the apparent magnitudes of the stars with 

 their numbers leads to no general conclusion, it is otherwise when we 

 view them in connection with their local distribution over the heavens. 

 If indeed we confine ourselves to the three or four brightest classes, 

 we shall find them distributed with tolerable impartiality over the 

 sphere ; but if we take in the whole amount visible to the naked eye, 

 we shall perceive a great and rapid increase of number as we approach 

 the borders of the Milky Way. And when we come to telescopic 

 magnitudes," or stars of so small a magnitude as to be invisible except 

 through a telescope, " we find them crowded, beyond imagination, 

 along the extent of that circle, and of the branch which it sends off 

 from it ; so that in fact its whole light is composed of nothing but 

 stars, whose average magnitude may be stated at about the tenth or 

 eleventh. 



" These phenomena agree with the supposition that the stars of our 

 firmament, instead of being scattered in all directions indefinitely 

 through space, form a stratum, of which the thickness is small, in com- 

 parison with its length and breadth ; and in which the earth occupies 

 a place somewhere about the middle of its thickness, aud near the point 

 where it subdivides into two principal laminae, inclined at a small angle 

 to each other. For it is certain that to an eye so situated, the apparent 

 density of the stars, supposing them pretty equally scattered through 

 the space they occupy, would be least in a direction of the visual ray 

 (as s A) perpendicular to the lamina, and greatest in that of its breadth, 



as 8 B, s 0, 8 D ; increasing rapidly in passing from one to the other 

 direction, just as we see a slight haze in the atmosphere thickening 

 into a decided fog-bank near the horizon, by the rapid increase of the 

 mere length of the visual ray. Accordingly, such is the view of the 



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