1892.] NEW-YORK MICROSCOPICAL SOCIETY. 29 



of proper poisons, and then to fix the paralyzed animal. Satis- 

 factory results were thus obtained by the use of chloral and differ- 

 ent alkaloids, such as cocaine, antipyrine, antifebrine, etc., with or 

 without subsequent poisoning. These paralyzing methods, which, 

 moreover, are not always effective, have the great disadvantage 

 that, through the action of the paralyzing reagents, which are in 

 most cases specific protoplasmic poisons, a simultaneous swelling 

 of the protoplasm occurs, so that, although the topographical con- 

 ditions are retained, the histological details are in many cases 

 destroyed. 



On that account a method is to be desired which will permit 

 metabolic animal forms to be fixed in a distended state, and at 

 the same time sufficiently insure their preservation, especially in 

 the case of those animals which have hitherto resisted all attempts 

 towards preservation. These results are to be obtained, as I have 

 subsequently shown in a series of experiments, with the aid of 

 hydroxylamine, i.e., with its hydrochlorate or sulphate, by means 

 of which the smooth and striated muscles of many Metazoa are 

 paralyzed to such an extent that a subsequent contraction, while 

 fixing them afterward, is hardly perceptible. A sufficient paralysis 

 is also obtained before a swelling of the protoplasm in the cells of 

 the paralyzed object is noticeable. 



A series of careful examinations with abundant material will 

 have to be made to determine to what extent hydroxylamine 

 poisoning may be used. The favorable results that I have ob- 

 tained with Protozoa, Hydrozoa, Actinozoa, Planarise, Annelida, 

 Rotifera, Mollusca, etc., lead me to believe that hydroxylamine, as 

 a paralyzing agent, will be more generally used. 



The following directions may be recommended in using hydrox- 

 ylamine : 



One per cent of the crystals of the commercial hydrochlorate, 

 which are usually impure, is dissolved in fresh water, and enough 

 carbonate of soda added to render the solution neutral. This 

 solution may be kept on hand in large quantities for use at any 

 time. Distilled water must not be used in preparing it, but in the 

 case of marine forms salt water must necessarily take the place of 

 fresh. It is not advisable to eUminate the hydroxylamine from 

 the hydrochlorate solution by adding an excess of carbonate of 

 soda, as the liquid then obtained would over-excite the animaL 



