Mechanical Science. 46t 



a dozen of these pins could be procured, well knows how to value 

 that trifle, the neglect of which has caused the loss of his voyage, 

 and might have led to that of his boat and his life also. 



Fixed towels cannot well be used when boats are to be hoisted 

 in alongside, as they are subject to be broken ; and they are often 

 inconvenient in getting in water casks, as well as in many other 

 cases. Hence, pins capable of being unshipped are preferable. 

 These are frequently lost, and the want is not always discovered till 

 it cannot be replaced ; or else it is not replaced without loss of that 

 time which is often so valuable at sea. Very often, also, the delay 

 of even a minute is rendered inconvenient or even dangerous; 

 when the boat is dragging alongside by the painter in a heavy sea, 

 and the vessel is either drifting or standing on. 



The drawing requires little explanation. By pulling at the 

 lower pin, the two upper are fixed at once, and on being unshipped 

 they hang secure from loss ; while the lower one serves as a spare 

 towel, should any be broken. As not one boat in twenty thousand 

 is provided with this invention, which is indeed scarcely known, it 

 will not perhaps be found undeserving a place in your Journal. — 



I am, &c. J. M. 



1 6. Cold Injection for Anatomical Preparation. — If a mixture of 

 Varnish and vermilion has a small quantity of water mixed with it, 

 it soon sets and becomes hard. This affords an excellent compo- 

 sition for anatomical injection, being very beautiful and very pene- 

 trating, (so much so, that it frequently returns by the veins,) and 

 requiring no heat to be applied to the subject. The writer of this 

 article frequently had, in the course of his medical education, the 

 office of preparing this injection, of which he has, however, unfortu- 

 nately forgot the proportions, and the particular nature of the varnish. 

 It was, he thinks, a spirit varnish ; the water was not mixed until 

 the instant the injection was wanted, when it was well worked up 

 with the syringe, and immediately thrown in ; in the course of a 

 night it would have set beautifully. This particular kind of injec- 

 tion was invented by an American anatomist of the name of Ram- 

 say, and preserved as a valuable secret by him for the exclusive 

 use of his own dissecting room. The proportions, &c. of the ingre- 

 dients will soon be attained by a few experiments. 



II, Chemical Science. 



1. Extraordinary Experiments on Heat and Sieain hy Mr. Per- 

 kins. — " I discovered that a generator at a certain temperature, 

 although it had a small crack in it, would not emit either water or 

 steam. This fact I mentioned to a very scientific friend, who ques- 

 tioned its accuracy, and to convince him I tried the experiment ; 

 but he concluded that the expansion of the metal must have closed 

 the fissure. To remove every doubt, I proposed to drill a small 



OCT.— DEC. 1827. 2 H 



