190 Dr. Spurgin's Outlines of a Philosophical 



giving a little snip sideways, both at the top and bottom, by 

 sticking a fish-hook in each corner of the skin, it was easily 

 stretched out before the microscope, and presented on the 

 screen a most beautiful picture of the veins and arteries in the 

 skin, with the blood circulating through them. In the arteries 

 we could plainly perceive the blood stopping, and as it were 

 receding a little at each dilatation of the heart, and then im- 

 mediately running forwards again at each contraction ; whilst 

 in the veins it rolled on in a continual current with inexpressi- 

 ble rapidity." To this Mr. Baker appends a note, wherein he 

 says, " When the arteries were magnified very much, by re- 

 moving the screen to a considerable distance, the alternate 

 expansion and contraction of their sides were very visible and 

 remarkable. After considering this " he proceeds, " as long as 

 we thought needful, we opened the abdomen, and extending 

 the muscles before the microscope, by the same means as we 

 had done the skin, we had the pleasure of viewing their struc- 

 ture, which we found to consist of bundles of transparent 

 strings or fibres, lying parallel to one another, and joined to- 

 gether by a common membrane. These strings or fibres ap- 

 peared through their whole length made up of minute roundish 

 vesicles ; or, in other words, seemed like rushes divided the 

 long way. We could not be certain of any circulation through 

 the muscles, though sometimes we imagined we saw a very 

 slow motion of some transparent fluid : but the object growing 

 dry and rigid, we proceeded to our last experiment, which 

 was to draw out gently a part of the frog's intestine, in order 

 to apply the mesentery to the microscope : and herein we suc- 

 ceeded so happily, that I believe the circulation of the blood 

 was never before seen in so distinct and fine a manner. No 

 words can describe the wonderful scene that was presented 

 before our eyes ! We beheld the blood passing through num- 

 berless vessels at one and the same instant, in some one way, 

 in others the direct contrary. Several of the vessels were mag- 

 nified to above an inch in diameter, and the globules of the 

 blood rolling through them seemed near as large as pepper- 

 corns; whilst in many of the minutest vessels only single glo- 

 bules were able to find a passage, and that too not without 

 changing their figure into that of oblong spheroids. We saw 

 likewise much better than we had done before, the pulsation 

 and acceleration of the blood in the arteries, in the manner 

 before described, and could clearly distinguish two or three 

 vessels lying over one another, with currents running different 

 ways. In short, it appeared like a beauteous landscape, where 

 rivers, streams and rills of running water are every where 

 dispersed. 



During 



