39'2 PHILOSOPHICAL TRANSACTIONS. [aNNO 1730. 



of the spermatic vessels, freed from their windings; cc, the same branches 

 dissected. 



Observations in dissecting an Ostrich. Bij Mr. Ranhij, F, R. S. N° 4 1 3, p. 27 5. 



Mr. Ranby adds two or three more observations, which escaped his notice 

 in his former dissection of the ostrich, in N° 386. 



And first, as to the eye, its figure, when taken out of the orbit, he thinks 

 particular, being almost triangular, with some little variation in the bony scales. 

 The contents of the stomach were of such a kind, that they were hardly 

 capable, without very great alteration, of passing the lower orifice, which is 

 very small. 



The diameter of the duodenum is much smaller than any of tlie intestines, 

 and free from valves, as are the jejunum and ileum, except the latter, which 

 has a few valves, as it approaches near the colon. The colon was uneven, 

 with very regular cells: these cells were formed by valves, which were on the 

 inside, and transversely situated, each making more than half a circle. 



The parts in other respects agree with the description given by the several 

 curious gentlemen, who have dissected this animal. 



A new Kind of Hydrometer, made by Mr. Clarke, and communicated to the 

 Society by J. T. Desaguliers, LL. D. F.R.S. N°413, p. 277. 



The hydrometer, by some called areometer, is an instrument commonly 

 made of glass, consisting of a stem ab, fig. 8, pi. Q, graduated by small beads 

 of glass of difi^erent colours, stuck on the outside, a larger ball, b, quite empty 

 as well as the stem, and a small ball, c, filled with quicksilver before the end 

 A, was hermetically sealed, in such manner, as to make the hydrometer sink 

 in rain water as deep as m, the n)iddle of the stem. Such an instrument does 

 indeed show the different specific gravity of all waters or wines, by sinking 

 deeper in the lighter, and emerging more out of the heavier liquors; but as 

 it is difficult to have the stem exactly of the same thickness all the way, which, 

 if it could be had, the same instrument would not serve for water and spirits, 

 sinking quite over head in spirits when made for water, and emerging in water 

 with part of the great ball out, when made for spirits. The hydrometer lias 

 only been used to find whether any one liquor is specifically heavier than 

 another; but not to tell how much, which cannot be done without a great 

 deal of trouble, even with a nice instrument. The hydrostatic;il balance has 

 supplied the place of the hydrometer, and shows the different specific gravity 

 of fluids to a very great exactness. But as that balance cannot well be carried 



