274 [December, 



THE NEW "NICKEL PIN." 

 BY H. GUARD KNAGGS, M.D., P.L.S. 



On the eve of the publication o£ my " improved pin " paper, it 

 is an agreeable surprise to receive from my good friend McLacMan, 

 a copy of the " Naturaliste," containing an account of a new '' nickel 

 pin," the more so as I have stated that my bronze pin is at best but a 

 makeshift, albeit superior to anything yet in use in this country ; that 

 no perfect pin is to be expected vrith the present metal basis — brass ; 

 and that nickel appeared to me to be the metal best adapted for the 

 pin of the future. Under these circumstances, it affords me great 

 satisfaction to find that Messrs. Deyrolle, of Paris, have just intro- 

 duced a nickel pin. The following is extracted from " Le Naturaliste " 

 of 15th of the present October : — 



" For collections of Coleopterous, Lepidopterous, and other insects, the pin is a 

 question of paramount importance. Ordinary pins of brass, even though well 

 tinned, frequently oxidize in the very body of the insect, and, in course of time, 

 have the great inconvenience of developing oxide of copper, produced by the grease 

 of the insects ; it forms around the pin, within the insect, a sort of pad which con- 

 tinually increases in size, and this distends the interior of the insect until it causes 

 it to burst. All collectors know this well to their sorrow, but we mention it only as 

 a reminder. To remedy this, people have made black varnished pins, and pins 

 coated with silver. The black pins are of two sorts, brass and steel ; should the 

 varnish crack, leaving the metal exposed, the same annoyance is produced by the 

 brass pins ; as for the steel ones, they rust, entailing in consequence the loss of the 

 specimen. The plated pins* have not any of these drawbacks, but they frequently 

 end in turning black, and presenting anything but a pleasing appearance to the eye. 



" The problem, then, was to find a metal which had not any of the defects 

 mentioned, but which might possess all the advantages. Nickel appeared to be in 

 every way indicated, but the difficulty was to adapt it to the special use for which 

 it was destined. For two years Messrs. Deyrolle have sought to make insect pins of 

 nickel, and by dint of study and experiment, they are enabled to offer nickel pins, 

 not of absolutely pure nickel, but of an alloy of which nickel is the principal com- 

 ponent part. Pure nickel, in point of fact, cannot conveniently be drawn into a 

 wire, it is brittle, and has but little power of resistance, it was therefore necessary 

 to find a compound of nickel which had all the advantages of the pure metal, and 

 it was to this class especially that their investigations were directed. The result 

 obtained is conclusive, and nickel pins bid fair to be in demand for all Entomological 

 collections, although the price may be a little higher than that of ordinary pins, 

 but the advantages are such that we doubt if collectors will hesitate. — L. F." 



At my request, Messrs. Deyrolle have obligingly forwarded 

 specimens of their wares, and it seems to me that although the nickel 



* N.B.— I think Messrs. Deyrolle will find that plated pins will not resist the action of insect 

 acids. Dr. Sharp's solid silver ones will ; and in my opinion, the tarnishizig of them is an im- 

 provement to their appearance : —but then, the price ! -H. G. K. 



