MILK. 425 



after the time of Hippocrates, but that people do not seem to 

 have used it as an article of food. It is obvious, from what Pliny 

 says, that even in his time butter was but little used by the Ro- 

 mans. " It is surprising," says he, " that the barbarous nations 

 which live upon milk should for so many ages have been igno- 

 rant of or have despised cheese, thickening their milk into an 

 unpleasant acid matter and into fat butter.* Cheese seems to 

 have been known to the Greeks and Romans at an early period, 

 and to have been used by them as an article of food. It is cu- 

 rious that Aristotle never alludes to butter in any of his writings, 

 though he is very particular in his account of cheese. 



Boerhaave considered milk as a natural emulsion, consisting of 

 an oil intimately mixed with a mucilaginous substance, f Neu- 

 mann considered it as analogous to chyle. He found that a pint 

 of cow's milk when evaporated to dryness left two ounces and two 

 drachms of residue ; but he found the milk of the same cow to 

 yield various proportions of dry residue at different times. He 

 gives a pretty minute description of butter, cheese, sugar of milk, 

 and whey, but takes no notice of the saline contents of that li- 

 quid, except that after combustion it leaves an alkaline ash.:f 



M. Rouelle made a careful examination of the saline constitu- 

 ents of milk in 1772, but he obtained nothing but sugar of milk, 

 chloride of potassium, and a very minute quantity of carbonate 

 of potash. His results were published in the Journal de Mede- 

 cine for 1773. 



In 1790, an elaborate memoir, by Parmentier and Deyeux, on 

 the Physical and Chemical properties of the Milk of Woman, Cow, 

 Goat, Ass, Sheep, and Mare, was published. To the authors of this 

 memoir was awarded the prize offered by the Royal Medical So- 

 ciety of Paris for the best essay on the above subject. In this 

 paper we find the first attempt at a chemical analysis of milk. It 

 was necessarily imperfect, but it contained a great many import- 

 ant observations, which facilitated the labours of other chemists. || 



In the year 1804, Bouillon-Lagrange published a memoir on 

 milk and lactic acid;1[ Scheele had long before (in 1780) made 



* Plinii, Natur. Hist. lib. xi. cap. 41. 



f Boerhaave's Chemistry, ii. 62, Shaw's translation. 



\ Neumann's Chemistry, p. 569. 



See Macquer's Dictionnaire de Chimie, Art. Lait. 



y See Journ. de Phys. xxxvii. 361 and 415. \ Ann. de Chim. 1. 272. 



