310 Proceedings of the Royal Society of Edinburgh. [Sess. 
Case 9. — Eleven months after gassing, still suffering from breath- 
lessness. 
Case 15. — Twelve months after gassing, still suffering from nausea 
and vomiting. 
Case 49. — Eighteen months after gassing, still suffering from dyspepsia, 
breathlessness, vomiting, sleeplessness. 
Case 45. — Twenty-two months after gassing, still symptoms of 
bronchitis. 
Thus the condition is one of very great importance from the point of 
view of the health of the army, the return of men to service, and the 
determination of pensions. 
Gases used for offensive purposes have been, and are, many and various. 
They may be divided into two groups : ( a ) cloud gas discharged from 
cylinders and carried by the wind ; (5) gas shells and gas bombs in which 
the poisonous substance is contained in the liquid form in the missile 
and is converted into a cloud of vapour on the explosion. The gas first 
used by the Germans in the spring and early summer, 1915, was almost 
certainly chlorine. It is certain that subsequently other gases were added. 
The above description of symptoms applies mainly to the 1915 gas. 
It is, of course, difficult to obtain exact information from a man who 
has been gassed as to the smell of the gas and his first symptoms, but we 
have been able to classify our cases as follows : — 
17 cases occurred in 1915. 
31 cases occurred in 1916 or 1917. 
18 were cases of cloud gassing. 
19 were cases of shell gassing. 
9 were poisoned with British gas. 
27 were poisoned with gas which was either probably or certainly 
German. 
As regards the blood change which we are describing, there is no marked 
difference. If the gassing is severe, the change is marked whether the 
gas be cloud or shell. Of the 15 cases in which the lymphocyte count 
was over 50 per cent., 5 were definitely cases of cloud gassing and 10 
cases of shell gassing. 
Our attention was first drawn to the blood changes in gas poisoning 
by the following case : — An officer was gassed (by British gas) October 
1915. He was exposed for about twenty minutes, but only complained at 
the time of feeling dazed. He suffered from cough for three months, and 
in September 1916, when in Craigleith Hospital, he complained of lassitude, 
and of some breathlessness and fatigue on exertion. He was anaemic- 
