1835.] Scientific Intelligence. 239 



1 1 . — Microscopal Objects . 

 Mr. Andrew Pritchard, Pickett Street, Strand, has just published 

 a useful little work for such persons as take an interest in examining 

 the beauties of the minute works of nature. It contains a list of 2000 

 microscopic objects, and is intended to serve as a guide for selecting 

 and labelling subjects of natural history, botany and mineralogy. Some 

 good observations are prefixed in reference to mounting microscopical 

 subjects, with remarks on the circulation of animals and plants. 

 III. — Isinglass. 

 From the experiments made by Mr. Smith in the United States, it 

 appears that the intestines of the fish the gadus merluccius furnish 

 the purest species of isinglass, (Journ. de Pharm. xx. 593.) not 

 inferior to that obtained from the sturgeon. The swimming bladder 

 of this fish is larger than that of other species of the same family. 

 It is cut out and washed with pure water, and then dried in the 

 sun. When partially dry it is pressed between wooden rollers as 

 thin as paper. The long stripes of isinglass which are met with in 

 commerce, are the intestines of the gadus morrhua. 



IV. — Prize of the Imperial Academy of Sciences of 

 St. Petersburg, for 1836. 

 For a considerable period it has been known that in some insects, 

 besides the abdominal nervous system, there exists another very deli- 

 cate series of nerves, situated on the dorsal portion of these animals. 

 Something analogous has been noticed in the class of annelides, as 

 in the leech, &c. This system deserves attention, because it seems 

 to bear some resemblance to the sympathetic nerve in vertebrated 

 animals. The Academy proposes for the subject of the prize for the 

 ensuing year, " Researches upon the different degrees of develope- 

 ment of the intestinal nerves in invertebrated animals, accompanied 

 with exact and detailed designs." They request attention to the 

 following points : — 



1. What is the developement of the intestinal nervous system in 

 those classes of invertebrate animals where it has been observed ? 

 (especially tenthredinates, ichneumones, and some sections of hemi- 

 pipterous and dipterous insects. ) 



2. Can a system of intestinal nerves be demonstrated in any inver- 

 tebrated animals besides those in which they have been already found? 



3. Can the different forms of the system of intestinal nerves be 

 reduced to certain general types ? 



4. Do these general types agree with established classifications, or 

 do the intestinal nerves follow a peculiar developement ? 



5. What relations subsist between the intestinal system, of nerves 

 and the rest of the nervous system, in reference to ramification and 

 size ? 



6. What reasons can be alleged for or against the analogy which 

 exists between this nervous system and the sympathetic nerve in 

 superior animals ? 



The academy will grant a prize of 200 ducats to the person who 

 shall resolve this question ; but in case none of the essays sent are 

 completely satisfactory, the author of the best of these will receive 

 according to the extent and importance of his work, an encouraging 

 prize of 100 or 50 ducats. 



The memoirs cannot be received after the 1st of August 1836. 



