776 keport— 1884. 



The result of the analysis was to show that the ash of the 'serum '(?) contained 

 •508 oxide of copper. This is considerably in excess of the maximum found by 

 Genth — viz., -338 per cent, in a duplicate determination of the copper in sample A. 

 The method of estimating the copper, shortly stated, was as follows: 500 c.c. serum 

 were evaporated to dryness over the water-bath, the residue then incinerated and 

 weighed, the resulting ash dissolved in hydrochloric acid with a slight addition of 

 nitric ; the copper then precipitated as sulphide by passing a stream of SH, gas 

 through the liquid ; the precipitate collected and washed with SEL water "(due 

 precaution being taken to prevent oxidation) ; the filter-paper and sulphide were then 

 transferred to a platinum capsule and burned ; this ash redissolved in nitric acid 

 and precipitated (this time as black oxide) by boiling with a slight excess of 

 caustic potash, the precipitate collected, and washed, and burned as before, after 

 moistening with nitric acid. 



As far as the salts are concerned the composition of Limulus serum appears to 

 be more like sea water than Mammalian serum; the latter contains about 28-5 

 per cent, chlorine, with only a little more than i per cent, of magnesia, whereas 

 the former contains about 55-25 per cent. c.c. and 6-25 per cent, magnesia. 



Some interesting points remain to be noted with reference to the organic 

 constituents of the blood ; the coagulum obtained from the freshly drawn blood 

 appears more albuminous than fibrinous ; the microscopic appearances presented 

 during its formation were not characteristic of fibrine, and the fresh clot itself gave 

 none of the recognised fibrine reactiors ; the expressed blue liquid gave no preci- 

 pitate with 10 per cent, chloride of sodium or saturated magnesium sulphate. A 

 partial coagulum of pure white colour was obtained on boiling, the liquid still 

 remaining blue. Genth states that along with this coagulum the copper is preci- 

 pitated ; we have not, however, verified this statement. 



In the case of the Octopus Fredericq concluded that the serum of the blood 

 contained a body allied to the proteids which he called Hsemocyanin, and which, 

 when acted on by acids, &c, splits up into an albuminoid substance containing no 

 metal, and a substance containing copper. The blood serum of Limulus probably 

 contains a complex proteid body, closely allied to Ilsemocyanin. In order to 

 preserve the serum for further investigation, thin films were dried on porcelain 

 slabs at the temperature ot the room, the dried films scraped oft" powdered, and 

 perfectly dried in a water-oven. A per-centage determination of the nitrogen in 

 this dried substance grave 11-322 per cent. N., for the ash-free substance this 

 would be equal to 15-459 per cent. 



We fully realise the incompleteness of our communication, but in consequence 

 of the limited time at our disposal and the want of a supply of ' fresh ' material, 

 we were unable to carry our investigation further ; should an opportunity of con- 

 tinuing it at any time present itself, we should endeavour, first, to separate the 

 copper-containing pigment to which the blood of Limulus probably owes its 

 peculiar properties ; secondly, to determine more precisely its relations to oxygen ; 

 and thirdly, to analyse the liver and blood clot. 



3. On Yaso-motor Nerves. By Professor H. P. Bowditch. 



The author gave an account of some experiments he had been making to 

 determine the need of vaso-motor nerves. He had employed an entirely new 

 method, namely, the use of the plethysmograph. 



4. Demonstration of the Co-ordinating Centres of Kroneclcer. 

 By T. 'Wesley Mills, M.A., M.D. 



5. On the Cardiac Nerves of the Turtle. 

 By Professor Hugo Keoneckee and T. Wesley Mills, M.A., M.D. 



(1.) The authors have experimented upon sea turtles, and found : (a) A vagus 

 trunk with the usual functional relations to the heart ; (b) Accelerantes nerves ; 



