BULLETIN 39, UNITED STATES NATIONAL MUSEUM. [HO] 



is known in commerce as " white carbon," and is put up in tlie form 

 of small square rods for use in intensifying the iiames of gaslight. The 

 material is very cheap, costing only 8 cents per pound wholesale, and 

 may be broken up into small j)ieces, wrapped in paper, and i^inned. The 

 use of naphthaline cones is not advisable in boxes containing delicate 

 si)ecimens, as ]t leaves a deposit which dulls the colors and encourages 

 greasing. The deliquescence of the naphthaline cones produces a black- 

 ish, oily residuum which will soil the lining of the box, and it is always 

 advisable either to pin a piece of blotting paper beneath the cone or to 

 wrap this in paper. 



Constant watchfulness is necessary to see that the eggs which have 

 been deposited and checked in development by the application of this 

 insecticide do not ultimately hatch and start a new generation in the 

 Insect box. 



Bisulphide of Carbon. — If the collection is found to be infested with 

 insect pests, it may be renovated by pouring a little bisulphide of carbon 

 into the boxes and closing them at once. This substance evaporates raj)- 

 idly and will destroy all insect life, and does not injure specimens or pins 

 nor stain the boxes. If infested specimens are received, these should be 

 inclosed in a tight box and treated with bisulphide of carbon before being- 

 added to the general collection, and it is always well for those who are 

 receiving pinned specimens by exchange or otherwise to keep a quar- 

 antine box of this kind on hand. 



Mercury Pellets. — The use of mercury pellets is recommended to free 

 boxes from Mites, Psoci, etc., and also to collect any x^articles of dust 

 which may gain entrance. A few small pellets of mercury, placed free 

 in the bottom of the horizontal box will, by the movement of the box, 

 be caused to roll to and fro and accomplish the desired end. 



Garholic Acid. — Mr. A.T. Marshall [Entomologist's Monthly Magazine, 

 Dec, 1873, p. 176) records that he washes the paper of his boxes with 

 the common disinfecting solution of carbolic acid in two-thirds water, 

 which dries mthout staining and protects the specimens from Psoci. 



A Means of preserving Insects in dry hot Countries. — In the '•^ Rorce 

 Societatis Entomologicce Rossicm,^^ XXIV, pp. 233, 234 (1889), M. A. 

 Wilkins, writing from Tachkent in Turkestan, alludes to the ineffi- 

 ciency of ordinary i3reservatives in Central Asia, on account of their 

 rapid volatilization through the hot dry air, so that if a collection be 

 neglected for only two or three months Anthreni are sure to be found 

 in the boxes. He has hit upon a plan which he finds effective, and at 

 the same time very simple. He employs India-rubber bands about 1^ 

 inches in width and less than the length of the boxes to which they are 

 to be applied. These bands are stretched over the opening line of the 

 boxes, and effectually prevent the entrance of the most minute destroy- 

 ers. Possibly a similar plan might be adopted in other countries with 

 a like climate. At any rate, the method has the merit of extreme sim- 

 plicity. (The Unt. Mo. Mag., Apr., 1891, p. 107.) 



