146 Royal Society : — 



is the formation of folds, which become more perceptible as the 

 animal increases in breadth, and which remain in the perfect 

 entozoon so long as it is confined to a small space, but dis- 

 appear when it gets to the space between the surface of a muscle 

 and the fascia covering it. The unfolding in this last situation 

 seems to be produced by the imbibition of fluid, and the consequent 

 distension of the ventral part. These more advanced stages of the 

 worm-form are best found in those specimens of diseased muscle 

 in which the perfectly developed Cysticerci abound. Their number 

 in proportion to that of the perfect animalcules varies considerably 

 in different specimens. 



I have always succeeded in finding some of those of the worm- 

 form along with the perfectly developed ones ; and in some cases 

 there are as many of one kind as the other. After they have 

 acquired a certain breadth — about one-twelfth, or the one-eighth of 

 an inch, — the central part of the cyst appears to be drawn inwards, 

 forming a hollow ; at the bottom of which, the granular material 

 is deposited from which the suckers, booklets, and calcareous 

 granules are formed, as above described. 



Jan. 10, 18.56. — Admiral Beechey, V.P., in the Chair. 



The following communication was read : — 



"On Insolinic Acid." By Augustus W. Hofmann, Ph.D., F.R.S. 



In attempting to purify cuminic acid by boiling with chromic 

 acid, I observed that this acid experienced, on the part of this 

 reagent, a progressive alteration. By twenty-four hours' ebullition, 

 cuminic acid is completely converted into an acid insoluble in alcohol 

 and ether, for which I propose the provisional name of insolinie 

 acid; purified by the ordinary processes, this body furnished on 

 analysis the following relations : — 



C9H4O,; 



but the analysis of the salts demonstrates that this formula must be 

 doubled, insolinic acid being a bibasic acid. 

 I have examined the following salts : — 



Insolinic acid Cjg Hg Og 



SUver salt Cjg (Hg Agg) Og 



Copper salt Cjg (Hg Cug) Og 



Barium salt C^g (Hg Bag) Og 



Calcium salt (at 1 00° C.) Cjg (Hg C&S Og 



(at 133° C.) C,g(HgCa,) Og 



Potassium salt (neutral) Cjg (Hg Kg) Og 



(acid) Cig(H7K) Og 



Potassium-sodium salt Cjg (Hg K Na) Og 



When considered by itself, insolinic acid has but slight claims on 

 the attention of chemists ; but when viewed in connexion with other 

 groups of bodies, it acquires increased interest. Some years since, 

 Gerhardt pointed out that to the homologous series of monobasic 

 fatty acids Cnj H^j O4, the lowest terms of which are formic and 

 acetic acids, there runs parallel a homologous series of bibasic 

 acids, C„2 Hnj-s Og, the simplest member of which is oxalic acid. 



