230 Mr. Waldie's investigations connected [No. 3, 



nauseous smell, but one not so characteristic as that produced by- 

 burning horn or wool for instance. 



Nevertheless not to neglect any means of obtaining information on 

 the subject, I not only, in the course of ascertaining the weight of 

 organic matter by burning it off, paid attention to the appearances 

 then presented, but afterwards made a few experiments on purpose. 

 But with all I cannot concur in the satisfaction expressed by Dr. Angus 

 Smith on the results, as quoted by Dr. Macnamara in his review of the 

 pamphlet.* He speaks of the remarkably clear insight given by 

 boiling down a few thousand grains of water and burning the residue. 

 He says, " We can by the eye and the smell detect humous and peaty 

 acids, nitrogenous organic substances, and nitrates, and estimate their 

 amount to a very useful degree of accuracy. We may even decide 

 by it the animal or vegetable origin of the matter." Now I have 

 carefully evaporated down repeatedly quantities of 50,000 and 100,000 

 grains of water and attended to these appearances, and the only 

 conclusion I came to was, that the information obtained was very 

 limited and unsatisfactory. I have also varied the experiment and 

 instead of burning the matter in an open platinum crucible have heated 

 it in a glass test tube. For some of the objects in view this is a 

 better plan ; and I compared in this way samples of water of the rainy 

 season, of the cold season, and of the hot season during flood tide. 

 For the latter, which is a mixture of river and sea water it is necessary 

 to mix the saline matter with some dry carbonate of soda, or better, to 

 evaporate the water to dryness with this admixture, in order to prevent 

 the evolution of hydrochloric acid vapours. The mouth of the tube is to- 

 be loosely closed with a glass stopper which is removed from time to 

 time to examine the smell and try with test papers. Examined in this 

 way, all those samples gave some ammoniacal vapour with no very 

 marked difference; all gave a somewhat urinous animal smell, but 

 not one the characteristic smell of burning flesh or horn : there were 

 slight variations, but none very distinct. The rainy season water gave 

 more of the smell of burning vegetable matter than the others, this 

 being the most distinctive point observed ; but altogether the informa- 

 tion obtained was very small. 



After the failure of all these plans, there remained but one likely to 

 * Indian Medical Gazette, April, 1866. 



