554 



NATURE 



[July 31, 1913 



the particles of which are seldom visible. In small 

 handmills of diorite this quartz appears to have 

 been ground up and the gold extracted from it, 

 but this appears to have been only profitable when 

 done by convict labour. Prospectors in modern 

 times, guided by the presence of these old work- 

 ings, have attempted to carry on the extraction 

 of the gold on a larger scale by modern methods, 

 but only in a few cases has it been found that this 

 can be done with profit, and most of the con- 

 cessions have been surrendered. 



The once-famous emerald-workings of Zabara 

 and Sikait in this district are opened in masses of 

 mica-schist, which alternate with gneiss, and con- 

 tain crystals of tourmaline and beryl — the clear 

 green varieties of this latter mineral constituting 

 the valuable gem emerald. It would appear, 

 however, that the ancients were satisfied with 

 specimens which, owing to their clouded or flawed 

 characters, do not appeal to the jewellers of the 

 present day, and, extensive as the old workings 

 undoubtedly were, there appears to be little 

 chance of the industry being revived. 



At several points on the Red-Sea coast, deposits 

 of gypsum and anhydrite, with pockets of sulphur, 

 occur, and concessions for the working of the 

 latter mineral have been granted. 



One successful mining industry, however, would 

 appear to be in full operation in the little island 

 of Tuberged, or St. John's, lying out in the Red 

 Sea, forty or fifty miles from the coast. Here, 

 in the midst of serpentine rocks, numerous beauti- 

 ful crystals of peridot (oliome) are obtained, and 

 the work of exploitation is being successfully 

 carried on. 



But although the expectations that this desert 

 region might become a centre of a great mining 

 industry do not seem likely of fulfilment, the 

 district is not devoid of interest to the man of 

 science. The rocks of the country exhibit, as 

 shown by Dr. Ball, a very great variety and not 

 a few remarkable characters, and the book before 

 us, with its abundant photographic and other illus- 

 trations, is well worthy of the attention which it 

 cannot fail to attract. J. W. J. 



THE PROBLEM OF A PURE MILK SUPPLY. 



The Milk Question. By Prof. M. J. Rosenau. Pp. 

 xiv + 309. (London: Constable and Co.; Boston 

 and New York: Houghton Mifflin Co., 1913.) 

 Price ys. 6d. net. 



THE milk question is very much to the fore 

 at the present time, and the appearance 

 of this work is therefore opportune, and, although 

 it embodies American views and practice, a great 

 deal of it is applicable to our conditions. The 

 NO. 2283, VOL. 91] 



author is well known as the present professor of 

 hygiene at Harvard, and former director of the 

 Hygienic Laboratory, Public Health and Marine 

 Service, U.S.A., who has contributed much to 

 the scientific investigation of milk and its bacterio- 

 logy. From the sanitary point of view the book 

 is sound, but, in addition, its author shows a 

 knowledge of the subject from the producer's point 

 of view, a side of the question which is frequently 

 overlooked by sanitary reformers in this country. 

 Written in simple language, it is a book for the 

 educated public generally, and many striking car- 

 toons and diagrams and terse sayings serve to 

 drive home the views enunciated, e.g. — 



" It (milk) requires scrupulous care from pasture 

 to pail, and from pail to palate." 



"The milk problem starts with the cradle, and 

 ends with the grave. Sometimes it leads to an 

 untimely grave." 



One or two considerations may be quoted as 

 illustrating the author's appreciation of the pro- 

 ducer's point of view. As regards the question 

 as to where the blame lies for an unhygienic milk 

 supply, the author says the tendency is for the 

 consumer to blame the producer, for the producer 

 to blame the consumer, for the middleman to 

 blame both of these, and for the health officer to 

 blame all three. Really, society must blame itself ; 

 we are suffering the inevitable penalties we must 

 pay for modern conditions of life, and of all those 

 concerned the farmer is least to blame for the 

 situation as it exists, and the consumer in the 

 city should be ever mindful that he has largely 

 brought the conditions upon himself. 



While expressing the opinion that bottled milk 

 is the ideal method of distribution, Prof. Rosenau 

 fully recognises its dangers and difficulties — diffi- 

 culties in the cleansing and handling of the bottles 

 and in transportation, which, he points out, is 

 expensive, bulky, the breakage is considerable, 

 and the return freight adds to the cost. He looks 

 forward to the time when milk will be dispensed 

 in some form of cardboard non-returnable package. 



On the mixing of milk from several cows, this 

 the author says is desirable, as it furnishes a 

 more uniform product, and tends to dilute infec- 

 tion if present ; this the framers of Bills in this 

 country might note. 



On the cells present in milk, it is stated that 

 normal milk has relatively few or no leucocytes, 

 and, when critically examined, the majority of 

 cells distinctly differs from leucocytes. 



The author would ascribe from 5 to 7 

 per cent, of all human tuberculosis to infection 

 with the bovine bacillus, but he is careful not to 

 suggest that this is necessarily derived from milk, 

 and quotes Weber's observations (made for the 



