4 Dr. Guy, on Microscopic Sublimates. 



That the test of sublimation succeeds with very small 

 quantities is sufficiently proved by the case of strychnine, of 

 which I have shown that the T^o^h of a grain will give four- 

 teen successive sublimates (of these eleven were obtained 

 prior to any change of form), and that one of the smallest of 

 these yielded three characteristic secondary sublimates. So 

 that sublimates may certainly be obtained consisting of as 

 little as the 3-oVnth of a grain.* 



That this mode of procedure is applicable to deposits from 

 solutions equally with the substance dissolved I showed long 

 since in the case of arsenious acid, and recently in that of 

 strychnine, by procuring five well-marked sublimates in suc- 

 cession from a spot of the alkaloid containing the -^J^^j-^ih. of a 

 grain deposited from its solution in aether. I have obtained 

 similar results from a solution of strychnine in benzole, and 

 from a solution of the acetate neutralized by the vapours of 

 ammonia. 



I have now said all that I deem necessary under the three 

 heads of novelty, largeness of scope, and practical utility, and 

 shall content myself, by way of preface, with repeating what 

 I have said elsewhere of one variety of the sublimates of 

 morphine, that " in the size and brilliancy of the crystals, 

 and the rapidity of their formation, they surpass every che- 

 mical reaction of which I have had experience.^^f I speak of 

 the reactions of the smoky sublimate of morphine with dis- 

 tilled water and one or two saline solutions ; but words 

 nearly as emphatic might be very justly used in speaking of 

 some of the reactions of strychnine. 



And now, having introduced my subject by these prefa- 

 tory remarks, I am keenly alive to the embarrassment pro- 

 verbially ascribed to a superabundance of materials. I find 

 that I have already accumulated a store of new and curious 

 microscopic objects, which I am naturally tempted to dis- 

 play, but am restrained by the fear that some at least of those 

 objects may prove to be exceptional, and not typical, speci- 

 mens. I have, therefore, determined to select, as the staple 

 of this paper, the two alkaloids — strychnine and morphine, 

 to describe and illustrate the leading varieties of their subli- 

 mates and some of their reactions, introducing other subli- 

 mates and their reactions only so far as may be required for 

 the purpose of illustration. I will speak of strychnine first, 

 and describe the results of an experiment made with this 

 alkaloid Avhen I had brought my paper to this point. I 



* ' Pliavmacculical Journal,' July, 1867. 

 ■j" Ibid., September, 1S07. 



