May 1, 1870.] 



HARDWICKE'S SCIENCE-GOSSIP. 



102 



Gossir,— the last word ou4he Sackbut question; and 

 with due thanks to "R. H. A." for the sure-footed 

 animal his " imagination " so kindly wishes to place 

 me on, beg to assure him that when I rode I pre- 

 ferred a faster steed. 1 liked riding to hounds, not 

 market ; had no objection to taking a stiff rail or 

 sound bank ; though I never affected stone walls or 

 a " bullfinch." 



Mr. Britten I really cannot have anything to say 

 to, since he comes the Grand Turk so strongly, and 

 visits " the brother of the sun and moon." There, 

 in such celestial company, together with "Dobbin," 

 I must leave him for the present, contenting myself 

 to " pick the bright and beautiful " nearer home. 



H. E. Watney. 



HINTS EOR DISSECTORS. 



OE the numerous paths into which natural science 

 draws its devotees none presents so many ad- 

 vantages and charms as that of dissection. It is a 

 skdful and beautiful art, which is easily learnt, and 

 I intend here to lay down a few simple rules, gleaned 

 from my own experience, for the benefit of some of 

 the readers of Science-Gossip, as I strongly incul- 

 cate the principle of studying the structure with 

 reference to the habits, and the habits with reference 

 to the structure. 



The implements are the first consideration. To 

 begin with, it is highly necessary to be supplied with 

 a sufficiency of good knives. Implements are expen- 

 sive, and I would advise, as cheapest in the end, 

 and far more convenient, the purchase of one of 

 Weiss's Dissecting-cases. It contains six knives 

 of graduated sizes, a pair of large and stout scissors 

 for rough work, a pair of smaller ones for more 

 delicate manoeuvres, a pair of strong forceps, a blow- 

 pipe for wafting away delicate tissues, distending 

 stomachs, &c, and three sharp hooks, each cormected 

 to a centre ring by a chain* which are exceedingly 

 useful for hooking back limbs and flaps of skin which 

 constantly are coming in the way. This set of in- 

 struments, which costs one guinea, is inclosed in a 

 neat and portable case. The great difficulty is to 

 keep the knives sufficiently sharp ; but if you live 

 near a town, it is easy to get them sharpened at a 

 cutler's at a trifling cost. 



The next requisite is a dissecting-board. It may 

 either be the top of a deal table, or, still better, a 

 separate oaken slab about two feet long and eighteen 

 inches wide, which will suffice for all specimens of 

 moderate size. You may then set to work in the 

 following manner. Place a good-sized deal table, 

 if possible used for no other purpose, in a window 

 with a good light ; spread a towel over it ; on your 

 right hand lay open your case of knives ; put your 

 oak board in the middle of the towel, the edges of 

 which spreading round are exceedingly handy for 



wiping the implements upon ; at the left-hand cor- 

 ner of the table let there be a saucer for the portions 

 of flesh you remove ; in front of you station a 

 tumbler of water, which is useful for a variety of pur- 

 poses ; supply lastly a handful of cotton wool to 

 stanch the flow of blood if perchance you pierce one 

 of the larger blood-vessels of your subject. Then 

 seating yourself on a high stool at the table and 

 taking some mammal, as for instance the rat, your 

 equipment is complete, and you may commence 

 work. 



I prefer to begin with the digestive organs, since 

 they are the parts most subject to corruption. With 

 the scissors cut a long slit across the abdominal coat 

 on a line with, and a little below, the ribs. Erom 

 the centre of this, cut another slit downwards be- 

 tween the legs, either folding back or cutting off 

 these flaps of skin, when a beautiful sight will be 

 disclosed. Remove the intestines first, and cutting 

 them through at the rectum and also at their con- 

 nection with the stomach, seize them with the 

 pincers with one hand, and with the knife in the 

 other, by steady pulls and dexterous cuts the great 

 mass will soon be freed. They may then be stretched 

 out, measured, and their internal coats, and the 

 nature of their contents, examined. Now disengage 

 the stomach, care being taken not to puncture it 

 in the operation. Its contents must be squeezed 

 out through the pylorus'and critically examined, — in 

 many animals much interest depending upon this 

 point. The stomach should then be washed, both 

 inside and out, in the tumbler of water, until it is 

 perfectly clean, and tying a piece of strong thread 

 tightly round the lower orifice and inserting the end 

 of your blowpipe into the upper one, tie a second 

 piece of thread round it, inclosing the pipe with it. 

 Holding the two ends tight, blow into the blowpipe 

 until the stomach is well distended with air ; then 

 with your mouth drawing out the pipe, at the same 

 moment pull the thread tight, and, securing it with a 

 knot, it may be hung up to dry. It is, however, a 

 performance which requires some knack to do suc- 

 cessfully : either it is filled too full, and on a rise of 

 temperature it bursts, or else enough air is not 

 supplied, and it rapidly shrivels. Practice, however, 

 will soon teach you the right medium. 



On the right side opposite the stomach is the liver, 

 with which the gall-bladder is connected. Beneath 

 all, and on each side, are the kidneys, the cellular 

 structure of which is interesting. 



The dissector should next proceed to the heart 

 and lungs. Having removed the diaphragm, that 

 large muscular membrane which divides the thorax 

 from the abdomen, it is far from easy to separate 

 the circulatory and respiratory organs from the rest 

 of the body, and it is necessary at the same time to 

 disengage the trachea or windpipe, which unavoid- 

 ably destroys to a certain extent some of the muscles 

 of the neck. It should be separated from the head 



