October, 1896.] 217 



SUGGESTIONS RESPECTING THE USE OF ALBO-CARBON 

 (IMPURE NAPHTHALINE). 



Br H. GUARD KNAGGS, M.D., F.L.S. 



The cheap albo-carboa, though less volatile and cousequently less 

 powerful than the purer naphthaline as a preventive of uiites and 

 Anthreni, seems, nevertheless, to fulfil the requirements of the more 

 costly article, and indeed, from certain points of view, to possess ad- 

 vantages over the latter. 



Being less, but still sufficiently, volatile, it is more lasting, and 



requires less frequent renewal no small gain in the case of a large 



collection ; for the same reason it suffers less loss when liquefied for 

 casting, moreover, it is manufactured in a spherical shape admirably 

 adapted for making " balls." 



How to make naplithaline "balls.'" — Materials : a pound of spherical 

 albo-carbon, four penny boxes of bead-headed, iuch-and-a-half (or 

 other lengths if required) steel toilet pins (with a drill of slightly less 

 thickness than the pins), discs punched from stout paper, and a little 

 varnish ; these, according to cookery book diction, 

 should cost about sevenpence, and be sufficient to make 

 a gi'oss. Mode : drill through the axis (at brokenoff 

 ends) of an albo-carbon sphere A, then push in a pin 

 B C, pick up a paper disc F on the pin point, and drive 



1'.-3£ the pin through a piece of cork till the disc rests at 



C about E, then touch with varnish the part of the pin 



between A and E, and also the upper surface of E, push 

 the disc home to D, and the "ball" is ready for use. 

 For cabinets, especially such as are provided with camphor cells, 

 I would suggest that, as even albo-carbon, when broken up, is un- 

 necessarily volatile, it would be a better plan to cast oblong slabs to 

 fit the cavities ; doubtless, if a sufficient demand were created, the 

 " Albo-Carbon Company" would be willing to turn out their commodity 

 in this form ; if not, the stuff may be broken up, put into a Florence 

 flask, melted under boiling water, and poured into suitable moulds, care 

 being taken to keep the fumes away from flames. To avoid accidents 

 it is advisable to conduct this operation on a gas stove under a 

 chimney. 



One more note respecting the effect of albo-carbon vapour on 

 specimens. 1 find that some Scoparice which were placed in it ni a 

 closely stopped bottle many months ago have 7iot failed in the leant 

 deqrec. Not only that, but these s|)(;cimcns, which were for a long 



