HYDROCYANIC ACID FOR FUMIGATION. 



Portions of ordinary silk ribbon, muslin, and boat-sail 

 drillincj saturated with acid showed no ill-etfects after a fort- 

 night. This also is of considerable practical importance, for it 

 indicates that the " rotting " of fumigation tents under present 

 methods is due to impurities from the ordinary generator. 

 Whether there is a corresponding reduction in the injury to 

 plants has not been determined. 



The dangerous nature of the acid must not be overlooked, 

 although, on the whole, with equal care in giving instructions 

 as to its use, I consider that it is no more dangerous than bisul- 

 l)hide of carbon. 



Under normal trade conditions, it may be possible for manu- 

 facturing chemists to produce the anhydrous liquid acid 

 economically, possibly from low-grade materials that are not 

 suitable for fumigation under present methods, and ship it as 

 a commercial article in place of the cyanide and acid. In such 

 case, it will simplify practical work, because the acid which 

 vaporises very quickly on exposure to the air, can be injected 

 through suitable openings in the tent or otlier enclosed space, 

 and thus do away with disagreeable and cumbersome generators 

 and the accompanving byproducts. The practical results should 

 be more reliable than by present methods. 



A lareer apparatus is being arranged with a view to ]:)roduc- 

 ing a sufficient c[uantity for field tests. 



AlcohoLOMETRIC Tables. — In connection witli tlie 

 article " Alcoholometry " in Sir Edward Thorpe's Dictionarv of 

 Aj^plied Chemistry, a series of tables is given for ascertaining, 

 from the si:)ecific gravity of mixtures of alcohol and water, the 

 l^roportions of alcohol and of proof spirit in such mixtures. 

 These tables have recently been extended, and are now published 

 in book form.* All who have to carry out frequent and accurate 

 determinations of alcohol, in liquids presumed to contain it, will 

 welcome the appearance of this handy little book. The names of 

 Blagden and Gilpin, of Tralles, Gay-Lussac and Sikes were long 

 familiar in connection with earlier tables, but those of Sir 

 Thomas Stevenson, compiled t,-^ years ago, were never surpassed 

 in accuracy or completeness. Sir Edward Thorpe has carefully 

 sifted all previous records, and the present volume is the final 

 result. For laboratory use its columns of widely spaced figures 

 in heavy Clarendon type ofTer the advantage of rapid and easv 

 reading for all who, in the distillation of industrial or other 

 spirits, desire special accuracy. The introduction preceding the 

 tables has an interesting account of the history of alcoholometry. 

 Rapidity of reading would be further advanced in future editions 

 by the provision of a marginal (thumb-hole) index to the tables. 



* " Alcoholometric tables." By Sir Edward Thorpe. C.B.. LL.D., 

 I-'.R.S., pp. xiv, QT. London : Longmans, Green & Co. 1915. 3s. 6d. net. 



