INSTRUCTIONS FOR COLLECTINQ INSECTS. * 179 



of large size, its revival raay be prevented by using oxalic acid, as 

 will be presently explained ; or if a " micro," the pin containing the 

 specimen should be fixed in a piece of cork and introduced into the 

 ammonia bottle. When using chloroform for benumbing the very 

 small moths, care must be taken that they do not fall or introduce 

 themselves into the drop used for this purpose ; for it ruins them 

 irretrievably ; therefore it should be spread by passing the glass which 

 contains the specimen over it; or, what is perhaps better, the top of the 

 collecting-box, (since it is in the field that this accident most frequently 

 occurs^ (should be covered with dark colored cloth glued to the surlace, 

 and this will absorb the liquid sufficiently to prevent its occurrence. 

 The collector should not, then, kill the smaller moths in the field with 

 this agent, but permit them to revive, and kill and set them after 

 returning home. It should never be applied to a varnished surface, 

 for it is a solvent of all varnishes. 



I would recommend this agent, then, to be used as the means of 

 abolishing the power of voluntary motion in moths, thus giving the 

 collector plenty of time during which he may pin them without 

 struggles or efforts to escape on their part. 



Oxalic acid is employed to kill large moths after they have been 

 pinned, and should be in the form of a strong ivater or alcoholic solu- 

 tion. In using it a steel pen, or a quill pointed like a pen, but without 

 the slit, should be dipped in the solution and passed into the side of 

 the thorax under the wings. The pen should be held there for a short 

 time and moved from side to side so that the whole of the solution 

 may enter the body. In killing large females it is best to make more 

 than one application. The objection to the acid is, that it leaves 

 a white spot, which is apt to spread and disfigure the specimen, but 

 this can generally with care be obviated. It is possibly scarcely 

 necessary to state that it is a violent poison when taken internally, 

 and that the bottle containing it should be the object of some care. 



Ammonia is an excellent agent for killing Lepidoptera ; the strong 

 spirits of ammonia should be used. In order to make use of it a wide- 

 mouthed, moderately deep glass jar should be obtained, and the edges 

 of the mouth ground down accurately on a piece of sheet lead with 

 emery and water, so as to allow a piece of heavy plate glass to close 

 it air-tight. If the jar rises in the centre, the bottom may be filled 

 with cotton so as to obtain a level surface. When the jar is to be 

 used, a piece of sponge is wet with a few drops of the ammonia, (the 

 operator should have some care for his fingers and nose at the same 

 time.) and the insect introduced, either pinned to a piece of cork or 

 free as the operator pleases. They soon become motionless, whatever 

 be their size, but will revive if taken out at once ; a half an hour is 

 sufficient to prevent the revival of the largest moths, but they may 

 remain without injury 24 or even 48 hours, perfectly relaxed and fit 

 for setting any time during that period, in consequence of the moisture 

 within the jar. The small Lepidoptera, tortrices and tineae, taken 

 in pill boxes, may be killed by placing the lid aslant previously to 

 introducing the box into the jar. The smallest kinds, the leaf miners, 

 nepticula and lithocalletis, should be pinned and set out immediately 

 they are dead. Green moths have their color affected by ammonia. 



