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HARDWICKE'S SCIEN CE -GOS SIP. 



"Vulcanite Cells.—" II. II. M." (S.-G., Dec, 

 page 2S2) inquires for practical information as to 

 experience with Vulcanite Cells. Mine are 

 Pumphrey's. I have tried them in two ways, and 

 succeeded well with both. I first tried gold size as 

 a cement. The plan was as follows : Lay the cell 

 on a flat surface, and paint over one side with 

 moderately thick gold size, then place the cell in 

 the exact centre of the slide : hold over the lamp 

 till hot, then place on the upper surface of the cell 

 another slip of glass, and put the whole into an 

 American clothes-peg until the cement is quite set. 

 The latter precaution is necessary because the cells 

 are sometimes slightly bent, especially if they have 

 been kept in a warm place. Baking in a cool oven 

 facilitates the hardening of the gold size. The 

 other plan was with marine glue, as follows : Cut 

 some marine glue into small bits, and put into a 

 bottle with about half its bulk of methylated chloro- 

 form. Cork the bottle loosely, and set in a warm 

 place till the glue melts. The heat of boiling water 

 is sufficient for this. Now cork closely and shake 

 up till well mixed ; keep the bottle warm for a little 

 while, occasionally shaking up. When cold, part 

 of the chloroform will be found at the bottom of 

 the bottle, and must be poured off by breaking up 

 the glue. Probably benzole would do as well as 

 the chloroform and would be cheaper. When re- 

 quired for use, warm the bottle and take up a litlle 

 of the glue on the end of a flat pointed splinter of 

 wood ; warm over the lamp 'and spread over one 

 side of the cell, as in using the gold size. Place the 

 cell, cement side downwards, on the slide ; warm 

 till the glue melts ; put on the top another slip of 

 glass, and put into a clip till cold. Lastly, scrape 

 off all superfluous cement, and clean the slide in 

 the usual manner. Of the two methods I prefer 

 the one with marine glue, as being less likely to be 

 acted on by balsam or preservative fluids, also be- 

 cause the slides are more easily cleaned, and the 

 cells are almost immediately ready for use.—/. H. 



Vulcanite Cells (p. 2S2). — In answer to 

 " Pi. H. M.," regarding the best method of attach- 

 ing Messrs. Pumphrey's Vulcanite Cells to the 

 glass slide, 1 beg to say that I find they adhere well 

 with marine glue, if roughened on a flat file on the 

 side intended to be attached to the glass.— P. E. B. 



Volition in Insects (see page 2G2). — We have 

 no proof, undoubtedly, that insects possess a 

 central brain. The evidence of dissection tends 

 to show a series of brains rather; and yet I 

 must still assert that there is a directing power 

 somewhere ; and can we localize it in any other 

 part save the head ? Take the instance of a 

 caterpillar : if the parts of its body did not move 

 in unison when it is crawling, wc might see the 

 head pointing forward, the claspers turning to the 



right, and the legs to the left. This does not occur. 

 Look at the same creature again when eating : by 

 smell or sight it is selecting a choice morsel of leaf. 

 To aid the jaws in their manipulations, the body 

 and legs are instantly obedient to the animal's will. 

 I do not think the example of the fly given proves 

 anything : motions of the muscles may take place 

 after the guidiug power has ceased to direct them. 

 Nor, again, can the possession of volition, and its 

 situation in any particular part, furnish any proof 

 that insects have a nervous system conveyiug 

 sensations aualogous to the higher animals. — 

 /. R. S. G. 



In a Tank.— A short time since I put a small 

 stone roach into a tauk containing an eel seven or 

 eight inches long, and a male Dyticus marginalia. 

 The next morning I found the conferva, which had 

 been growing very luxuriantly, all torn up for a 

 space of some six or seven inches square, and rolled 

 up into a case about five inches long and one inch in 

 diameter, and open at the end nearest the bottom. 

 Considerable force must have been'used, as a tuft of 

 Starwort, which had been there all the winter, was 

 completely uprooted and rolled into the case. I 

 left it iu the water for about a fortnight, watching 

 it closely all the time, but saw no use made of it, 

 and all the inhabitants seem quite jolly together. — 

 J. G. Oclell. 



Musical Coavs.— That pigs are not the only 

 animals who take a delight iu musical sounds, may 

 be proved by the following incident, of which I was 

 a witness on more than one occasion. Opposite to 

 our house was a large field, in which some twelve 

 or thirteen cows were put during the summer 

 months. One day a German band commenced to 

 play in the road which divided the house from the 

 field. The cows were quietly grazing at the other 

 end of the field, but no sooner did they hear the 

 music, than they at once advanced towards it, and 

 stood with their heads over the wall attentively 

 listening. This might have passed unnoticed ; but, 

 upon the musicians going away, the animals fol- 

 lowed them as well as they could on the other side 

 of the wall, and, when they could get no further, 

 stood lowing piteously after their retreating forms. 

 So excited did the cows become, that some of them 

 ran round and round the field to try and get out, but 

 finding no outlet, returned to the same corner where 

 they had lost sight of the band; and it was some 

 time before they seemed satisfied that the sweet 

 sounds were really gone. It seems a strange 

 coincidence that both the pigs and cows were 

 charmed by music produced by a German band.— 

 L. E. Caffemta, Belmont Road, Liverpool. 



Moss Labels.— Can any reader of Science-Gos- 

 sip inform me where Lists of Mosses for herbarium 

 labels Cim be procured ? — M. LT. 



