290 On Animal Fluids, 



again asserted by my adversary, is from the figure of cry- 

 stals. I have to remark, in addition to my former obser- 

 vations, that their forms alone rarely or never, even when 

 perceivable with the unassisted organ of vision, dosbigly 

 denote unequivocal properties ; and when not perceivable 

 without the medium of glasses, we know from past expe- 

 rience the figures are to be considered as still more equivo- 

 cal, I might say deceptive. If these crystalline forms are 

 now adnutted as justly distinguishing properties of certain 

 substances, it is in consequence of repeated observation on 

 larger quantities by direct vision, — " quae sint oculis sub- 

 jecta fidelibus," — but even then not without concomitant 

 other well ascertained properties. 



Secondlv — Great depentlence seems to be placed on the 

 acetate produced by combining acetic acid with the sa- 

 line matier afforded bv incineration. This was said to be 

 acetate of soda, which dissolved in alcohol, while potash was 

 found in the residue left undissolved by the alcohol. I 

 have searched the pages of the memoir under examination 

 again and again, for the evidence in support of this allega- 

 tion ; but here, and on many other occasions, is a mere asser- 

 tion, except a partial support from the serum of the blood, 

 as will be seen hereafter. For, 1. With regard to the sa- 

 line matter of the fluid of the spina itfiila I find these words : 

 *' the alcoholic solution being decanted ofl' and evaporated 

 to dryness, a residue supposed to consist of acetate of soda 

 was obtained." Here no mention is made either of an ex- 

 periment to prove whether the acetate was that of soda or 

 ot potash, but it was supposed to be acetate of soda. As 

 to the undissolved matter containing potash, there is not 

 thai I can find even aw.ird written. This too has been sup- 

 posed. 2. With regard to the second fluid examined, that 

 of hydrocephalus interims, we are told " the analysis was 

 conducted in the same manner as in the former:" — of 

 course the existence of soda in the alcohol and of potash 

 undissolved are not proved, but 1 presume here also sup- 

 posed. 3. In the other animal fluids, viz. of ascites, of hy- 

 drmhorax, and hydrops pericardii, as well as subsequently 

 of the hydrocele ; of the hydatids, of the thyroid gland, and 

 of a tumour of the chest, no such experiment as that of 

 compoundintj; an acetate is mentioned. 4. in the cxperi- 

 inenls, however, on the saline matter of the serum of the 

 blood, an acetate was compounded which dissolved in alco- 

 hol, the words of the author being, " the alcoholic residue 

 contrary to my expectations exk'iiiled traces of potash, both 

 by means of tartaric acid and oxyiiiuriate of platina." 



This, 



