ABSTRACTS. 



909 



After speaking of varieties, planting, cultivating, and harvesting the 

 Sorghum plant, the writer goes on to describe four processes of clarifica- 

 tion (suited to different-sized factories), the object of which is, in each 

 case, " to remove solid impurities from the raw mill juice before heating 

 the latter much, then to remove the impurities coagulated by heating the 

 juice to boiling point, and finally to remove impurities which separate 

 during concentration of the juice to 25° density." 



The operations of filtering, skimming, evaporation, and settling ara 

 gone into, and the pamphlet concludes with a summary containing many 

 useful hints to syrup-makers. — C. H. C. 



Sparrows, Relations of, to Agriculture, By Sylvester D. Judd 

 {U.S.A. Dep. Agr. Bull. No. 15, Die. Biol. Survey; 19 figs., 1 diag.). — 

 A most interesting account of investigations undertaken during a course 

 of years by the U.S.A. Biological Survey Department into the feeding 

 habits of the various species of American sparrow. The English or 

 European house-sparrow, which was misguidedly introduced into America 

 about 1850, is, we are told, a most unmitigated nuisance, but all the 

 native varieties are quite the farmer's friends, preferring weed-seed to 

 grain, noxious to useful insects, and wild berries to garden fruit. 



The writer lays stress upon the fact that, in calculating the com- 

 parative value or injuriousness of any bird to agriculture, it is as important 

 to notice what he leaves as what he eats, and to this end it is necessary 

 to carry on the investigations in three ways : — 



1. By weighing separately the varying contents of a sufficient number 

 of birds' crops to be able to decide, with approximate accuracy, on the 

 relative proportions of useful to neutral and injurious matter devoured 

 by the species. 



2. By experimenting upon captive birds to find what food they will 

 generally prefer and what they will entirely reject. 



3. By carefully examining the available food supply in the birds' known 

 feeding-grounds, so as to determine what they might have eaten and did 

 not, and the proportions which they themselves established between the 

 different articles of their diet. 



The writer then takes each member of the sparrow family by name, 

 gives an exhaustive account of its habitat and food, and sums up, more or 

 less strongly, in favour of each, except in the case of Nuttall's sparrow, of 

 vThich the usefulness seems doubtful, and of the English sparrow, which 

 he entirely condemns. 



He vindicates even the English sparrow, however, against the charge 

 which has been brought against the whole family, of distributing weed- 

 seed. A sufficient number of examinations have been made to show that 

 the mutilation of the seed either in the beak or in the gizzard is so com- 

 plete as to make germination later impossible. — M. L. H. 



Spraying. By L. Mangin (Bull. Soc. Hort. Loirct, tome vi. No. 13, 

 p. 569 ; 1901). — Directions for preserving evergreen plants from insects 

 by spraying with solutions of sulphate of copper or naphthol. — E. A. B. 



Spraying*. By L. C. Corbeti; {U.S.A. Exp. Stu. West Virginia 

 University Bull. 70). — For the prevention of scab on Apples, and also 



