At the Liverpool Police Court a firm was prosecuted for selling peas containing copper equal to 24 grains of sulphate to the pound tin. A warranty produced.

A Liverpool grocer was fined 20s. and costs, for selling peas containing copper equal to 2-6 grains of the sulphate to the pound. +

At Bradford vendors have been fined for selling coppered peas, the metal equalling 1 to 2 grains to the pound. ‡

CHINESE PEAS.

§ 101. A pea or bean, much used in China in the form of cheese, is the Soia hispida.§ Its composition, according to G. H. Pellet, is as follows:

* Sanitary Record, vi. 335. + Ibid., vi. 351.

Ibid., vii. 63.

§ The pea-cheese is considered, in China and Japan, a very important food. The peas (Soia hispida) are soaked in water for about 24 hours, then strained; they are next ground to a thin paste with some of the water which has been put on one side. The grinding is effected by a mill. The matters are filtered, and the filtrate is concentrated by heat; and after skimming once or twice is cooled, the caseine coagulated by plaster, and a salt, which appears to be chloride of magnesium, added. The cheese is grayish-white, and has the following general composition :

Per cent.

LENTILS.

§ 102. The lentil is the seed of the Erbum lens, one of the Leguminosa. Lentils are grown and eaten in all parts of the civilised world, and are highly nutritious. They contain, according to H. Ritthausen, 5.9 per cent. of legumin, and their general composition is as follows:

The general composition of the ash is as follows:

§ 103. The beans eaten in this country are mostly the kidney bean, Phaseolus vulgare, and the broad bean, Vicia faba. The following is the average composition of these vegetables :

The percentage composition of the ash of these different beans

has the following composition:

Broad bean. Kidney bean.

From both the broad and the kidney bean a small quantity of cholesterine can be separated. According to Ritthausen, the legumin of the kidney bean has a composition different from that of other legumins; for while the percentage of nitrogen in pea and millet legumin amounts to 16.77 per cent., that of kidney bean legumin has only 14.71 per cent.

PART IV.-MILK, CREAM, BUTTER, CHEESE.

MILK.

HISTORICAL INTRODUCTION.

§ 104. Before the birth of experimental philosophy, the origin rather than the composition of substances was the subject of inquiry, and of fanciful and more or less ingenious conjecture. Milk to the ancient, as well as to the modern world, was a fluid of great virtue. Aristotle affirmed, "Lac est sanguis concoctus, non corruptus," which may be translated, Milk is elaborated, not decomposed, blood-an opinion identical with that held by nineteenth-century philosophers.

Averroes, Avicenna, and others, reasoning in part from the difficulty with which many females conceive while suckling, held that milk was altered menstrual blood. Avicenna, indeed, formularised this doctrine by declaring that the menstrual blood of the pregnant was divided into three parts-part going to nourish the fœtus, part ascending to the breasts, and the remainder being an excrementitious product. These opinions may be traced to writers of a much later, almost modern epoch. The ancients were acquainted with only three constituents of milk-viz., butter, with which they used to anoint their infants; caseine, which they precipitated with vinegar; and the whey from which the curd and butter had separated, and this, up to the early part of the sixteenth century, constituted the whole of what was known as the composition of milk. Placitus enumerates no more constituents than Avicenna, but devotes several pages to the then all-important question as to whether milk was hot, cold, or moist, and concludes that animal milk, as compared with that of human, is cold, human with that of animal, hot. Placitus* was an upholder of the menstrual theory. Panthaleont similarly cites with approval the dictum that milk is a fluid superfluity, twice concocted in the breasts, and gravely discourses, as stated, whether it is hot

* Sexti Placiti Papyriensis: De Natura et Usu Lactis, MDXXXVIII. It would appear, according to this author, that the Germans in his time used the milk of all animals, for he enumerates the milk not only of cows, mares, and goats, but also of pigs.

+ Summa Lacticinorum, 1528.

or cold. He recognises three parts only in milk-viz., serum, butter, and curd. His treatise is mainly composed of references to the ancients, and the usual disputations as to whether milk is hot or cold. The first mention of a fourth constituent of milk occurs in a curious work by Bartoletus, published in 1619. Bartoletust called it the "manna" of milk, or "nitrum seri lactis." In his days sulphur, mercury, and a saline principle, were considered as the three active essences of all things, and as existing in all things; hence, Bartoletus, from the yellow colour of butter referred it to a sulphur principle, the whey, doubtless from its mobility, to quicksilver, and the curd to a saline element. He then compares milk with blood, also composed of a sulphurated, saline, and mercurial principle. The discovery of Bartoletus for a long time was not known beyond Italy. A French apothecary, named Bartholomew Martin, writing in 1706,§ enumerates the constituents of milk as three-butter, analogous to sulphur, serum to mercury, and cheese to salt; but was not acquainted with milksugar, although eight years before Ludovico Testi|| had written an entire treatise on it, calling it by the name it now bears.

In the early part of the eighteenth century, Leeuwenhoek discovered the microscopical characters of milk. He saw that it was a fluid containing many globules. Some, which he judged to be of a buttery nature, rose to the top of the liquid; and others, again, rather sank to the bottom, and were evidently different in composition. Some twenty years later, A. Donné, in his Cours Microscopique,** published some beautiful plates of several kinds of milk, fresh and sour, human and animal, exhibiting the globules, &c., drawn to scale with wonderful accuracy.

§ 105. In the early part of the eighteenth century flourished the school of the illustrious master Boerhave, who laid the

* There are several other treatises on milk about this epoch, but they nearly all, as, for example, that of Gesner (Libellus de Lacte et Operibus Lactarius, auth. Conrado Gesnero, Medico), consist of commentaries on the opinions of older writers, and are of no value.

+ Bartoletus was an Italian physician, a professor at Bologna and Mantua, B. 1586, D. 1630. His work is entitled, Encyclopædia Hermetico-Dogmatica sive Orbis Doctrinarum, Physiologica, Semiotica, et Therapeutica. Bononia, 1619, 4to. The quarto is little over 300 pages, and is divided into five parts, viz., (1.) Physiology, (2.) Hygiène, (3.) Pathology, (4.) Semiotics, and (5.) Therapeutics.

"Enim in lacte videre est, in quo serosa portio mercuriali liquori, butyrosa sulphureæ, caseosa vero saline substantia respondet. Ita in sanguine alia sulphurea, alia saline, alia mercurialæ substantiæ proportionaliter respondet." § Traité du Lait, par Barth. Martin, Apothicaire, Paris, 1706. Relazione concernente il Zucchero di Latte, 1698.

¶ Letters, tome ii., 4to edition, 1722.

** Cours de Microscopie, 8vo. Paris, 1844; Atlas, in folio. Paris, 1845.