38 •* THE ANIMAL FLOIDS. 



fixation. In my remarks perhaps I cannot entirely avoid 

 repetition of objections already produced. 

 Figure of crys- The first kind of proof, that soda and not potash is pre- 



. not a dea " sent, again asserted by my adveisarv, is fom the figure of 

 give proof. » » / j . . .. . - 



crystals. I have to remark in addition to my fanner obser- 

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

 perceivable with the unassisted organ of vision, do singly 

 denote unequivocal properties: and when not perctivable 

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

 ence the figures are to be considered as stiil more equivocal, 

 I might say deceptive. If these crystalline forms are now 

 admitted as justly distinguishing properties of certain sub- 

 stances, it is in consequence of repeated observation on 

 larger quantities by direct vision, " quae sint oculis subjecta 

 fidehbW; but even then not without concomitant other 

 well ascertained properties. 

 Acaicactd Secondly, great dependence seems to be placed on the 



t n»ve acetate produced by combining acetic acid with the saline 



d acetate r . . . s . 



of soda. matter afforded by incineration. This was said to be acetate 



of soda, which dissolved in alcohol, " while potash wa» 

 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 as- 

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

 Id of spina as will be seen hereafter. For 1st, with regard to the saline 

 matter of tiie fluid of the spina bifida, I find thtse words, 

 *' the alcoholic"?olution being decanted off 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 

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

 the undissolved matter containing potash, there is not even 

 that I can find a word written. This top, has been 

 Supposed. 

 Fluid of by- 2, Wi'h regnrd to the second fluid examined, that of 

 jirocephalus hydio<-ei>bilv,,s interims, we are a acrid, " the analysis was 

 conducted. in the samp manner as in the former" — of course 

 the existence of soda in the alcohol, and of potash undis- 

 solved, is not proved, but here also supposed. 



3. In 



.uta. 



