﻿82 FIELD AND FOREST. 



or under other conditions ; and in the presence of a weak acid, or even 

 water, the starch would become purple or blue ; but, on the other hand, 

 were the corpora amylacea subjected to the process I propose, their 

 true character would be seen. Were they, or any part of them com- 

 posed of tubular structure they would be converted into discs, some 

 of which would expand into globules resembling starch, while the 

 membranous portion, if present, would not change in structure, unless 

 the sulphuric acid were used too strong, when it would wholly disappear 

 by solution forming new products. 



Since writing the above, it occured to me that still greater care should 

 be employed in making tests for amylaceous matter in blood, than I 

 have heretofore made. I therefore renewed my experiments, com- 

 mencing as follows : Four new slips of glass, i by 3 inches, were im- 

 mersed in c. p. concentrated sulphuric acid, together with all the glass 

 rods and phials used in my experiments. If amylacious matter were on 

 any of the Vessels or glass rods used, the acid would quickly destroy it. 

 These respective instruments were washed in distilled water, and each 

 submitted to the action of the flame of a Bunsen burner. A pen-knife 

 was subjected to the same flame until it changed from a white to straw 

 color. My hands were washed, and dried with leather, and my fore- 

 finger being punctured with the point of the knife, a drop of blood was 

 removed from it and placed on one of the plates of glass, 1 by 3 inches. 

 The acids and iodine were used as described for blood. A power of 

 one hundred diameters was employed to examine the results of the 

 chemical action, when several well-defined blue amylaceous forms 

 were seen, and when examined by the higher powers exhibited no 

 structure, but resembled spots of starch spread out. A second experi- 

 ment was made, and similar blue amylaceous spots were seen moving 

 about in the liquid. I next made experiments with chemicals, from 

 the same phials, combining them without the blood, and placing them 

 on other slides carfully prepared, but no blue amylaceous matter was 

 seen. When tincture of iodine, muriatic and sulphuric acids are com- 

 bined on a microscopic slide, and viewed with a power of about 100 

 diameters, purple liquid globules are seen ; but these, in the absence 

 of cellulose or cholesterine never assume the blue color. 



To use high powers for the examination of boiled starch will avail 

 nothing, because it is without structure. One of my experiments, 

 alluded to by Dr. Lawson, editor of the London Microscopical Journal, 



