188 



Ehrhorn (E. M.). Division of Plant Inspection — Hawaiian Forester 

 & Agriculturist, Honolulu, xv, no. 11, November 1918, pp. 458- 

 463. [Received 17th February 1919.] 



During September 700, and during November, 496 bags of wheat 

 from Australia were fumigated before delivery, being infested with 

 several species of weevils. 



During October two parcels of acorns and chestnuts were fumigated 

 for weevils, and two palms were fumigated for mealy bug. 



Protection of Insect-eating Birds in St. Vincent. — Agric. News, 

 Barbados, xviii, no. 436, 11th January 1919, p. 15. 



It is notified for general information that the following insect- 

 eating birds are fully protected by law in St. Vincent : — Tick bird 

 {Crotophaga ani), Barbados blackbird [Quiscalus fortirostris), Tyrannus 

 rostraius, Elainea martinica and Ardea caerulea. 



The preservation of these valuable birds is necessary, because they 

 assist materially in controlling pests damaging local crops. For 

 example, the first three are known to feed on the cotton stainer 

 {Dysdercus delauneyi) as well as on other insects, and Ardea caerulea is 

 a noted enemy of the destructive mole-cricket {Scapteriscus didactylus). 



Haywood (J. K.). A Method for Preparing a Commercial Grade of 

 Calcium Arsenate. — U. S. Dept. Agric, Washington, DC, Bull, 

 no. 750, 5th October 1918, 10 pp. [Received 21st February 1919.] 



Attention has recently been drawn to the use of calcium arsenate 

 as a substitute for lead arsenate, principally because of the cheapness 

 of lime as compared with lead oxide. Though not recommended for 

 use alone on tender foliage, it gives excellent results on some of the 

 more resistant plants, as well as very promising ones when combined 

 with other sprays, especially sulphides, which cause the breaking up 

 of lead arsenate to a greater or less extent. 



The best method of making calcium arsenate from lime and arsenic 

 acid consists in: — (1) using a good grade of lime containing a high 

 percentage of CaO ; (2) slaking the lime to a paste as smooth as 

 possible, for upon this depends the smoothness of the final product, 

 as well as the readiness with which the Hme and acid react. From 

 3 to 3| times as much water, by weight, as lime should be used. 

 After standing for a time and then being thoroughly mixed, twice as 

 much hot water as used for slaking should be added. (3) The lime 

 and arsenic should be in such proportion that the weight of actual 

 CaO used will be equal to that of AsgOg used. This gives a product 

 with a molecular ratio slightly over 4, which is necessary if the 

 soluble AsPs is to be kept down to desirable limits. (4) The acid, 

 at room temperature, should be added to the lime as quickly as possible, 

 and the liquid should be stirred well until it becomes alkaline to 

 phenol-phthalein. (5) It should be filtered to as dry a state as 

 possible, but not washed, and if a dry product is desired it should be 

 dried directly. (6) It should then be crushed in a suitable disinte- 

 grator, or ground if necessary. 



To produce 100 11). of commercial calcium arsenate by this process 

 will require 45 lb. CaO (approximately 50 lb. of a high grade lime) to 



