611 



DiNGLER (M). Ueber den Arsengehalt von Blattern, Friichten und 

 Wein nach Vorbehandlung mit Schweinfurtergriin. [The Arsenic 

 Content of Leaves, Fruits and Wine after Spraying with Paris 

 Green.] — Zcitschr. angeiv. Ent., Berlin, viii, no. 1, September 

 1921, pp. 187-188. 



At the request of the Imperial Biological Institute for Agriculture 

 and Forestry, experiments were undertaken to test whether plants 

 sprayed with a mixture of lime and Paris green, either with or without 

 an adhesive, retain sufficient of the poison to be harmful to health. 

 Grapes, cabbage leaves, a very hairy variety of gooseberry, and pears 

 were sprayed during the period in which arsenicals should be pro- 

 hibited according to the Imperial Public Health Service, i.e., during 

 the chief flight-period of the second generation of the vine moths. 

 At various dates, beginning a few weeks after spraying and ending 

 when the material was ready for consumption, the arsenic was vola- 

 tilised as arsenic trichloride, and the distillate was titrated with an 

 iodine solution of 1 per cent, normal strength. Some of the plants 

 were washed before the tests and others were not. No trace of arsenic 

 could be detected in grapes. The highest amount of arsenious acid 

 present in 10 grammes of desiccated vegetables (100 grammes of 

 fresh material) was 0-00249 gramme ; in this case an adhesive had 

 been mixed with the spray and examination took place immediately, 

 the material being thoroughly washed ; one month after spraying no 

 arsenic was present except in one case, where traces of a deposit were 

 found. One nionth after being sprayed the gooseberries did not 

 show any amount of arsenic worth considering. Pears yielded traces 

 of arsenic only when still unripe and when an adhesive spray had 

 been used. 



These tests are considered to show conclusively that the proposed 

 restrictions are superflvious. 



EscHERicH (K.). Uraniagnin in Tafelform. [Urania Green in Block 



Form.] — Zeitschr. angeiv. Ent., Bcylin, viii, no. 1, September 

 1921, pp. 188-189. 



Hitherto Paris green has been marketed chiefly as a powder. Urania 

 green, which is a form of this arsenical, is now available in blocks 

 sufficient for 100 htres (22 gals.) and divided into five equal sections. 

 The convenience of this is obvious, and the idea will certainly be 

 adopted for other preparations of a similar character. 



Mottenechte Stoffe. [Moth-proof Yabxics.]— Zeitschr. angew. Ent., 

 Berlin, viii, no. 1, September 1921, pp. 189-191, 2 figs. 



As a result of investigations [R.A.E., A, ix, 5] a preparation for 

 rendering wool fabrics proof against the clothes moth [Tineola 

 bisclliella] has been placed on the market under the name of " Eulan 

 F." Wool can be proofed at a very low cost by immersion in a cold- 

 water solution of the chemical followed by rinsing. Carpets and 

 upholstering fabrics and horsehair stuffing can also be treated. It 

 is, of course, impossible to say at present whether the protection can 

 be rehed on for many years, but on chemical grounds a permanent 

 effect seems likely. The appearance and feel of treated material 

 remain unchanged, and there is no disagreeable smell. 



