May 1, 1867.] 



HAKDWICKE'S S CIEN CE- GO S SIP. 



105 



729), and those by Vulpian (Etude physiologique des 

 Venins Crapauds, du Triton et de la Salamandrc 

 terrestre, Mem. de la Soc. de Biologie, 1856, p. 122), 

 there has recently been published a paper on the 

 poison of the " Salamandra metadata" by Dr. 

 Zalesky, who has isolated and examined the poi- 

 sonous principle of the secretion of this animal. 

 This investigation has been carried out in the well- 

 known laboratory of Professor Hoppe-Seyler, at 

 Tubingen, and is especially interesting on account 

 of its being the first accurate chemical examination 

 of an animal poison. 



The poison was obtained by scraping the head 

 and back of the animal with a teaspoon, and collect- 

 ing thereby the whitish secretion, which is of a 

 viscid consistency, possessing a strong alkaline 

 reaction, an acrid bitter taste, and a faint but not 

 unpleasant odour. Prom this secretion, the poison- 

 ous principle was isolated by a somewhat lengthened 

 chemical process, and found to be a true alkaloid, 

 possessing all the characteristic properties of this 

 class of substances. That this alkaloid (Saman- 

 drine) is in reality the poisonous principle of the 

 secretion of the salamander has been proved by 

 direct experiments, which show that it belongs to 

 the most potent poisons. A fish, a duck, and a dog 

 to whom it had been administered, died of its effect. 



There are a few instances on record in which cases 

 of poisoning are ascribed to the salamander; but 

 they are perhaps on the whole not well enough 

 authenticated to be accepted as facts; it would 

 therefore be interesting if this subject should 

 receive some attention from those of your readers 

 who may have an opportunity of making observa- 

 tions or collecting trustworthy evidence. 



H. M. 



CLIP POP, ZOOPHYTE TROUGH. 



TN the ordinary zoophyte trough used for exa- 

 -*■ mining under the microscope animal or vege- 

 table objects in water in a free, unconfined con- 

 dition, the position of the inclined glass plate is 

 regulated by an ivory wedge in front, supported by 

 a whalebone spring at the back inside the trough ; 

 but this construction has the objection that the 

 spring is liable to be upset sideways by an acci- 

 dental touch of the hand, or by catching the stage 

 bracket of the microscope, causing the object in view 

 at the time to be suddenly washed out of the field 

 and perhaps lost altogether, to the disappointment 

 of the observer. 



Por the purpose of removing this objection, I have 

 devised, in conjunction with Mr. Pumphrey, a double 

 clip that takes the place of the wedge and spring, 

 and is found very satisfactory and convenient, and 

 quite free from risk of disturbance accidentally. This 

 clip is shown full size in the accompanying drawing, 

 and is made of a piece of ebonite about one-eighth 



of an inch thick, having two long cuts upwards from 

 the bottom end, inclined to one another so as to leave 

 a wedge-shaped piece between them, corresponding 

 to the ordinary wedge for regulating the position of 

 the inclined glass plate; whilst the front and back 

 portions act as spring clips, holding the front plate 

 of the trough and the inclined plate, the two cuts 

 in the clip being made narrower at the bottom end 

 than the thickness of the glass plates, so as to hold 

 them by a slight spring pressure, as shown in the 

 detached view of the clip. 



, •• — — '-' | ■-;---• ' - - - - 



( 



I 



i 

 ! 



I 



Fig. 74. Zoophyte Clip. Full size. 



By sliding this clip up or down, the width of the 

 space between the plates that contains the objects 

 under examination, is regulated in the same manner 

 as by the ordinary wedge ; and the clip at the same 

 time holds the inclined plate securely in each posi- 

 tion, without any risk of being displaced or moved 

 unintentionally, as the clip is entirely free from the 

 back of the trough, and keeps clear of the stage 

 bracket in all positions whilst the trough is being 

 moved upon the microscope stage. 



The narrowness of this clip is also an advantage, 

 as the ordinary wide wedge occupies an inconvenient 

 amount of the field of view. 



The inclined glass plate, which is usually made as 

 high as the back of the trough, is cut down in this 

 case to the same height as the front of the trough, 

 as this is found to be a sufficient height, and allows 

 the clip to be shorter. 



A specimen of these clips is enclosed herewith, and 

 they are now made by Mr. Pumphrey, Paradise 

 Street, Birmingham, from whom they can be ob- 

 tained. In the drawing the larger of the two sizes 

 of zoophyte trough in ordinary use is shown, but 

 the same clips suit also the smaller size of trough, 

 and in that case the original height of the inclined 



glass plate is not altered. 



W. P. Marshall. 



